<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2022 Workiva-->
<!--r:c608ddb9-dfee-484b-86cb-42e6685b4f90,g:598bf620-965a-4204-b6cf-954348ae7e87-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.nninc.com/role/CondensedConsolidatedBalanceSheets" xlink:type="simple" xlink:href="nnbr-20220930.xsd#CondensedConsolidatedBalanceSheets"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/CondensedConsolidatedBalanceSheets" xlink:type="extended" id="i9f974f1b797445ee8e57ce318a4ce9ae_CondensedConsolidatedBalanceSheets">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_ed0f5eea-94be-4cb0-8e96-6fde0e8e591b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_6dd7cf37-baf3-4b58-991c-b7fdddcd3f39" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_ed0f5eea-94be-4cb0-8e96-6fde0e8e591b" xlink:to="loc_us-gaap_AssetsAbstract_6dd7cf37-baf3-4b58-991c-b7fdddcd3f39" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrentAbstract_04ffe0f4-13ae-4fcd-a995-8dd7d51265e9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6dd7cf37-baf3-4b58-991c-b7fdddcd3f39" xlink:to="loc_us-gaap_AssetsCurrentAbstract_04ffe0f4-13ae-4fcd-a995-8dd7d51265e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_f62fdc42-87e9-45f5-9a2b-dadcd66cb525" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_04ffe0f4-13ae-4fcd-a995-8dd7d51265e9" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_f62fdc42-87e9-45f5-9a2b-dadcd66cb525" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_e5d943c2-4eb1-4382-be08-1b5dffac7b73" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_04ffe0f4-13ae-4fcd-a995-8dd7d51265e9" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_e5d943c2-4eb1-4382-be08-1b5dffac7b73" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_61905f0e-0e91-4a45-9d9f-074786494e14" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_04ffe0f4-13ae-4fcd-a995-8dd7d51265e9" xlink:to="loc_us-gaap_InventoryNet_61905f0e-0e91-4a45-9d9f-074786494e14" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxesReceivable_4cad00b4-61b1-4355-b841-bb40d143a771" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxesReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_04ffe0f4-13ae-4fcd-a995-8dd7d51265e9" xlink:to="loc_us-gaap_IncomeTaxesReceivable_4cad00b4-61b1-4355-b841-bb40d143a771" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsCurrent_5dde2866-fea9-4512-b6dc-f44629e9a519" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_04ffe0f4-13ae-4fcd-a995-8dd7d51265e9" xlink:to="loc_us-gaap_OtherAssetsCurrent_5dde2866-fea9-4512-b6dc-f44629e9a519" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_0f684a13-71ef-4d85-8805-8dc14a248a05" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_04ffe0f4-13ae-4fcd-a995-8dd7d51265e9" xlink:to="loc_us-gaap_AssetsCurrent_0f684a13-71ef-4d85-8805-8dc14a248a05" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_54356e08-5cb6-48c0-a3b4-5c34e94e5456" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6dd7cf37-baf3-4b58-991c-b7fdddcd3f39" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_54356e08-5cb6-48c0-a3b4-5c34e94e5456" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_01ab25e5-472c-4061-bd5f-cca67ff403e6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6dd7cf37-baf3-4b58-991c-b7fdddcd3f39" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_01ab25e5-472c-4061-bd5f-cca67ff403e6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_050c888f-3945-4d53-8ee8-4c7d7800cb13" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6dd7cf37-baf3-4b58-991c-b7fdddcd3f39" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_050c888f-3945-4d53-8ee8-4c7d7800cb13" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_5665390a-25c0-429c-8cb8-2243e82f4fa0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6dd7cf37-baf3-4b58-991c-b7fdddcd3f39" xlink:to="loc_us-gaap_EquityMethodInvestments_5665390a-25c0-429c-8cb8-2243e82f4fa0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxAssetsNet_8827b95c-1038-4495-a42b-4d539a9e4604" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredIncomeTaxAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6dd7cf37-baf3-4b58-991c-b7fdddcd3f39" xlink:to="loc_us-gaap_DeferredIncomeTaxAssetsNet_8827b95c-1038-4495-a42b-4d539a9e4604" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_68eba977-5ebf-47b4-b19a-da63295eb8cd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6dd7cf37-baf3-4b58-991c-b7fdddcd3f39" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_68eba977-5ebf-47b4-b19a-da63295eb8cd" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_df9601c7-160f-40b3-ac5a-692be5f40de7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_6dd7cf37-baf3-4b58-991c-b7fdddcd3f39" xlink:to="loc_us-gaap_Assets_df9601c7-160f-40b3-ac5a-692be5f40de7" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_ed0f5eea-94be-4cb0-8e96-6fde0e8e591b" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_a758fe87-9b94-47ac-b12a-0e099b465c04" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_a758fe87-9b94-47ac-b12a-0e099b465c04" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_a236a46d-1fd0-4d4d-88fe-fbbf9f732a99" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_a758fe87-9b94-47ac-b12a-0e099b465c04" xlink:to="loc_us-gaap_AccountsPayableCurrent_a236a46d-1fd0-4d4d-88fe-fbbf9f732a99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_1be1fd01-7080-4419-afb2-2d8743e6e2a2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_a758fe87-9b94-47ac-b12a-0e099b465c04" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_1be1fd01-7080-4419-afb2-2d8743e6e2a2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedIncomeTaxesCurrent_ba0f33f4-b0b3-409c-a366-61bb17830af7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccruedIncomeTaxesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_a758fe87-9b94-47ac-b12a-0e099b465c04" xlink:to="loc_us-gaap_AccruedIncomeTaxesCurrent_ba0f33f4-b0b3-409c-a366-61bb17830af7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_7f5d789f-cf20-442c-9d81-ad17af8132ae" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_a758fe87-9b94-47ac-b12a-0e099b465c04" xlink:to="loc_us-gaap_LongTermDebtCurrent_7f5d789f-cf20-442c-9d81-ad17af8132ae" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_f7e2b90a-48e2-4a99-a6c7-eed508658ad5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_a758fe87-9b94-47ac-b12a-0e099b465c04" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_f7e2b90a-48e2-4a99-a6c7-eed508658ad5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent_1cb9fdab-ab74-47ff-9709-a2f66d2033ed" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_a758fe87-9b94-47ac-b12a-0e099b465c04" xlink:to="loc_us-gaap_OtherLiabilitiesCurrent_1cb9fdab-ab74-47ff-9709-a2f66d2033ed" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_76f2b185-bf26-4192-aa37-9f520779cd58" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_a758fe87-9b94-47ac-b12a-0e099b465c04" xlink:to="loc_us-gaap_LiabilitiesCurrent_76f2b185-bf26-4192-aa37-9f520779cd58" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_559b2087-cecf-4441-a903-6ab6583a0514" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_559b2087-cecf-4441-a903-6ab6583a0514" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_b37aa4af-c88a-4dde-9a37-da001dfea44b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_b37aa4af-c88a-4dde-9a37-da001dfea44b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_7b2c61a8-ed44-42ce-b391-bd945c41e337" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_7b2c61a8-ed44-42ce-b391-bd945c41e337" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_bf604439-1332-4859-a3b3-6a09c7182a8d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_bf604439-1332-4859-a3b3-6a09c7182a8d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_8facda9f-ff3e-4c73-93ed-3b14546c555d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:to="loc_us-gaap_Liabilities_8facda9f-ff3e-4c73-93ed-3b14546c555d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_e14494c8-9e40-4842-96af-41844e323081" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:to="loc_us-gaap_CommitmentsAndContingencies_e14494c8-9e40-4842-96af-41844e323081" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests_dd388694-060d-42d9-9d3d-ad74a102564c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:to="loc_us-gaap_TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests_dd388694-060d-42d9-9d3d-ad74a102564c" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_4cd3ff67-329b-4bda-a27b-ec367a6473d6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:to="loc_us-gaap_CommonStockValue_4cd3ff67-329b-4bda-a27b-ec367a6473d6" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_5b4f9745-c128-4a9a-9468-8d9f296c0cd1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:to="loc_us-gaap_AdditionalPaidInCapital_5b4f9745-c128-4a9a-9468-8d9f296c0cd1" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_bc37c4f9-6500-4123-8fa1-560508121bda" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_bc37c4f9-6500-4123-8fa1-560508121bda" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_b48ca886-3132-46cc-bf89-8736a65f3803" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_b48ca886-3132-46cc-bf89-8736a65f3803" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_2bfd6763-e99c-4bb2-af43-a2889bedf3ec" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_2bfd6763-e99c-4bb2-af43-a2889bedf3ec" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_69aae0ce-2b48-4519-89a6-786538d15cd0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_15ec304b-75c1-408d-8bcf-a6f926390e1c" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_69aae0ce-2b48-4519-89a6-786538d15cd0" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_76744626-f9d9-4635-b3f8-f6e678d824e5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_ed0f5eea-94be-4cb0-8e96-6fde0e8e591b" xlink:to="loc_us-gaap_StatementTable_76744626-f9d9-4635-b3f8-f6e678d824e5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_04b202f3-2d1c-4ef1-81e1-066893e20973" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_76744626-f9d9-4635-b3f8-f6e678d824e5" xlink:to="loc_us-gaap_StatementClassOfStockAxis_04b202f3-2d1c-4ef1-81e1-066893e20973" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_04b202f3-2d1c-4ef1-81e1-066893e20973_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_04b202f3-2d1c-4ef1-81e1-066893e20973" xlink:to="loc_us-gaap_ClassOfStockDomain_04b202f3-2d1c-4ef1-81e1-066893e20973_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_bab246fd-75bc-48c9-88a0-d6cc5f670116" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_04b202f3-2d1c-4ef1-81e1-066893e20973" xlink:to="loc_us-gaap_ClassOfStockDomain_bab246fd-75bc-48c9-88a0-d6cc5f670116" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesDPreferredStockMember_7a9b65db-b9b2-4d07-bc85-b1aeaea4c6ea" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeriesDPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_bab246fd-75bc-48c9-88a0-d6cc5f670116" xlink:to="loc_us-gaap_SeriesDPreferredStockMember_7a9b65db-b9b2-4d07-bc85-b1aeaea4c6ea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesBPreferredStockMember_ca1b5c4c-d576-40ea-9d11-41e9d1ffc655" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeriesBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_bab246fd-75bc-48c9-88a0-d6cc5f670116" xlink:to="loc_us-gaap_SeriesBPreferredStockMember_ca1b5c4c-d576-40ea-9d11-41e9d1ffc655" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/CondensedConsolidatedBalanceSheetsParenthetical" xlink:type="simple" xlink:href="nnbr-20220930.xsd#CondensedConsolidatedBalanceSheetsParenthetical"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/CondensedConsolidatedBalanceSheetsParenthetical" xlink:type="extended" id="i990ecc300d144079aef02195008fd560_CondensedConsolidatedBalanceSheetsParenthetical">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_4c28818a-99e8-49c6-b848-d31417bd8087" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_e905e2b7-fd7e-440e-8f50-bb79f3efce95" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4c28818a-99e8-49c6-b848-d31417bd8087" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_e905e2b7-fd7e-440e-8f50-bb79f3efce95" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization_6b9dfa50-f537-4cae-825c-86944ad78279" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4c28818a-99e8-49c6-b848-d31417bd8087" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization_6b9dfa50-f537-4cae-825c-86944ad78279" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_202c3751-2c76-4dc8-8770-f4047df1bae1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4c28818a-99e8-49c6-b848-d31417bd8087" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_202c3751-2c76-4dc8-8770-f4047df1bae1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_3efc4782-63e2-4101-bbea-62f1ca04a077" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4c28818a-99e8-49c6-b848-d31417bd8087" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_3efc4782-63e2-4101-bbea-62f1ca04a077" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_e3e53418-93c1-4462-becf-576344201f55" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4c28818a-99e8-49c6-b848-d31417bd8087" xlink:to="loc_us-gaap_PreferredStockSharesIssued_e3e53418-93c1-4462-becf-576344201f55" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_4aae2409-422b-458e-ab32-218aa45d4edc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4c28818a-99e8-49c6-b848-d31417bd8087" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_4aae2409-422b-458e-ab32-218aa45d4edc" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_94babdab-83fa-4720-a2a8-42b89149b32f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4c28818a-99e8-49c6-b848-d31417bd8087" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_94babdab-83fa-4720-a2a8-42b89149b32f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_2fd2a428-01dd-4760-add9-d086abfdbace" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4c28818a-99e8-49c6-b848-d31417bd8087" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_2fd2a428-01dd-4760-add9-d086abfdbace" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_d6dd02e0-ec7a-461d-b3df-cad3c0c7e692" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4c28818a-99e8-49c6-b848-d31417bd8087" xlink:to="loc_us-gaap_CommonStockSharesIssued_d6dd02e0-ec7a-461d-b3df-cad3c0c7e692" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_c5391cbc-ad93-4510-a39c-49ba1d48d60d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4c28818a-99e8-49c6-b848-d31417bd8087" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_c5391cbc-ad93-4510-a39c-49ba1d48d60d" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_61cedbcc-3d10-46e0-8d5d-575d49a4b7fd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_4c28818a-99e8-49c6-b848-d31417bd8087" xlink:to="loc_us-gaap_StatementTable_61cedbcc-3d10-46e0-8d5d-575d49a4b7fd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_9dd1339c-73a5-4c7b-809f-ad9439853f3d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_61cedbcc-3d10-46e0-8d5d-575d49a4b7fd" xlink:to="loc_us-gaap_StatementClassOfStockAxis_9dd1339c-73a5-4c7b-809f-ad9439853f3d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_9dd1339c-73a5-4c7b-809f-ad9439853f3d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_9dd1339c-73a5-4c7b-809f-ad9439853f3d" xlink:to="loc_us-gaap_ClassOfStockDomain_9dd1339c-73a5-4c7b-809f-ad9439853f3d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_f3dea2da-e34b-4fd8-99ac-cc4edc6c1898" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_9dd1339c-73a5-4c7b-809f-ad9439853f3d" xlink:to="loc_us-gaap_ClassOfStockDomain_f3dea2da-e34b-4fd8-99ac-cc4edc6c1898" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesDPreferredStockMember_58b4c612-a0ea-4c86-97b8-933b0ba96c43" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeriesDPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_f3dea2da-e34b-4fd8-99ac-cc4edc6c1898" xlink:to="loc_us-gaap_SeriesDPreferredStockMember_58b4c612-a0ea-4c86-97b8-933b0ba96c43" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesBPreferredStockMember_aa6938d9-2d66-427d-ab15-0e450fddf9d8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeriesBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_f3dea2da-e34b-4fd8-99ac-cc4edc6c1898" xlink:to="loc_us-gaap_SeriesBPreferredStockMember_aa6938d9-2d66-427d-ab15-0e450fddf9d8" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/CondensedConsolidatedStatementsofChangesinStockholdersEquity" xlink:type="simple" xlink:href="nnbr-20220930.xsd#CondensedConsolidatedStatementsofChangesinStockholdersEquity"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/CondensedConsolidatedStatementsofChangesinStockholdersEquity" xlink:type="extended" id="ie724b4dcfbc74ad18df4115ba36c32e2_CondensedConsolidatedStatementsofChangesinStockholdersEquity">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_b3f5c5e1-6536-4101-9771-9f5840345eaf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MovementInMinorityInterestRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b3f5c5e1-6536-4101-9771-9f5840345eaf" xlink:to="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesIssued_c341bc82-d03a-42f5-9be9-41824c64e8e9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:to="loc_us-gaap_SharesIssued_c341bc82-d03a-42f5-9be9-41824c64e8e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_7d5f5930-ce6d-4e42-b19a-f9931886951c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:to="loc_us-gaap_StockholdersEquity_7d5f5930-ce6d-4e42-b19a-f9931886951c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_82c0ab95-3fd9-4601-954b-5a0537cf21db" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:to="loc_us-gaap_NetIncomeLoss_82c0ab95-3fd9-4601-954b-5a0537cf21db" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPreferredStockPaidinkind_089653ce-9b75-49e6-8518-d0b27146e6e3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DividendsPreferredStockPaidinkind"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:to="loc_us-gaap_DividendsPreferredStockPaidinkind_089653ce-9b75-49e6-8518-d0b27146e6e3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_847bbac5-1aa3-45e3-9d88-7fce5f6ba194" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_847bbac5-1aa3-45e3-9d88-7fce5f6ba194" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_b7289df3-6397-423d-85fa-9bf50f41bfab" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_b7289df3-6397-423d-85fa-9bf50f41bfab" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_aeff92db-056f-45be-b50d-01498b0be754" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_aeff92db-056f-45be-b50d-01498b0be754" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_1ed8b151-af0f-4fa8-adea-5b7f4e2cc204" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_1ed8b151-af0f-4fa8-adea-5b7f4e2cc204" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_SharesPaidForTaxWithholdingAndForfeitedForShareBasedCompensation_bc4e07de-aa86-4a81-ba61-66bcd329abad" xlink:href="nnbr-20220930.xsd#nnbr_SharesPaidForTaxWithholdingAndForfeitedForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:to="loc_nnbr_SharesPaidForTaxWithholdingAndForfeitedForShareBasedCompensation_bc4e07de-aa86-4a81-ba61-66bcd329abad" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_AdjustmentsRelatedToTaxWithholdingAndForfeitedForShareBasedCompensation_0db5a231-1398-4f76-b92d-f200db164ea3" xlink:href="nnbr-20220930.xsd#nnbr_AdjustmentsRelatedToTaxWithholdingAndForfeitedForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:to="loc_nnbr_AdjustmentsRelatedToTaxWithholdingAndForfeitedForShareBasedCompensation_0db5a231-1398-4f76-b92d-f200db164ea3" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_AdjustmentstoAdditionalPaidinCapitalAdjustmentstoPerformanceSharesVestingEstimates_0eb4f5af-1cf4-4bd8-a60c-8cbe1b966e40" xlink:href="nnbr-20220930.xsd#nnbr_AdjustmentstoAdditionalPaidinCapitalAdjustmentstoPerformanceSharesVestingEstimates"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:to="loc_nnbr_AdjustmentstoAdditionalPaidinCapitalAdjustmentstoPerformanceSharesVestingEstimates_0eb4f5af-1cf4-4bd8-a60c-8cbe1b966e40" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_AdjustmentsToAdditionalPaidInCapitalAdjustmentsToPerformanceSharesVestingEstimates_f75873f5-bc7e-401b-9562-4218e6e5c4bf" xlink:href="nnbr-20220930.xsd#nnbr_AdjustmentsToAdditionalPaidInCapitalAdjustmentsToPerformanceSharesVestingEstimates"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:to="loc_nnbr_AdjustmentsToAdditionalPaidInCapitalAdjustmentsToPerformanceSharesVestingEstimates_f75873f5-bc7e-401b-9562-4218e6e5c4bf" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax_44e3bea4-87a2-4861-b1bb-9c52c8ba344c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax_44e3bea4-87a2-4861-b1bb-9c52c8ba344c" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax_283d5775-e4e7-4deb-b659-f94a59c50d10" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax_283d5775-e4e7-4deb-b659-f94a59c50d10" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_577db4b0-48b4-4dd0-a139-bb1cbc17578d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInMinorityInterestRollForward_43314a95-bf82-4526-b657-253f79c1d1e1" xlink:to="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_577db4b0-48b4-4dd0-a139-bb1cbc17578d" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesIssued_eeef91cf-8855-4e81-bf88-7d070502c7d6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesIssued"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_6f53440b-c7f8-4a98-97c8-7aac42130a68" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_b144a475-56d8-4ff6-86eb-41e84f67a247" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_b3f5c5e1-6536-4101-9771-9f5840345eaf" xlink:to="loc_us-gaap_StatementTable_b144a475-56d8-4ff6-86eb-41e84f67a247" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_dbd8959e-7f67-461c-8d23-9732eed9921a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_b144a475-56d8-4ff6-86eb-41e84f67a247" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_dbd8959e-7f67-461c-8d23-9732eed9921a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_dbd8959e-7f67-461c-8d23-9732eed9921a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_dbd8959e-7f67-461c-8d23-9732eed9921a" xlink:to="loc_us-gaap_EquityComponentDomain_dbd8959e-7f67-461c-8d23-9732eed9921a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_6c0b313f-50e1-401c-992a-22e09477b9e2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_dbd8959e-7f67-461c-8d23-9732eed9921a" xlink:to="loc_us-gaap_EquityComponentDomain_6c0b313f-50e1-401c-992a-22e09477b9e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_b57e310d-2eb5-4547-8ca8-0ee839850916" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_6c0b313f-50e1-401c-992a-22e09477b9e2" xlink:to="loc_us-gaap_CommonStockMember_b57e310d-2eb5-4547-8ca8-0ee839850916" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_fdacc5f8-2875-4f4d-ad7e-7ae9cc0ad772" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_6c0b313f-50e1-401c-992a-22e09477b9e2" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_fdacc5f8-2875-4f4d-ad7e-7ae9cc0ad772" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_53e61d5e-8479-46f9-8009-082ee6b1f62a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_6c0b313f-50e1-401c-992a-22e09477b9e2" xlink:to="loc_us-gaap_RetainedEarningsMember_53e61d5e-8479-46f9-8009-082ee6b1f62a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_89a848cb-e41f-4d84-bde9-5ba2e179b2da" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_6c0b313f-50e1-401c-992a-22e09477b9e2" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_89a848cb-e41f-4d84-bde9-5ba2e179b2da" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/SegmentInformationContinuingOperationsbyReportableSegmentDetail" xlink:type="simple" xlink:href="nnbr-20220930.xsd#SegmentInformationContinuingOperationsbyReportableSegmentDetail"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/SegmentInformationContinuingOperationsbyReportableSegmentDetail" xlink:type="extended" id="i902d987dad384a48b01c53323ac10ce9_SegmentInformationContinuingOperationsbyReportableSegmentDetail">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_a88ce501-d1c2-4f3a-8b39-416bb9fcdb64" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_0635fd75-88f6-4d05-94f9-9a1befb3018a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a88ce501-d1c2-4f3a-8b39-416bb9fcdb64" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_0635fd75-88f6-4d05-94f9-9a1befb3018a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_268047c9-b7e9-49da-abf8-6762fc349ac0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a88ce501-d1c2-4f3a-8b39-416bb9fcdb64" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_268047c9-b7e9-49da-abf8-6762fc349ac0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_045f51e3-53be-47d4-a47d-a88e9a0ca66f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a88ce501-d1c2-4f3a-8b39-416bb9fcdb64" xlink:to="loc_us-gaap_OperatingIncomeLoss_045f51e3-53be-47d4-a47d-a88e9a0ca66f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_50f34717-039a-4070-979b-d2e6a83de35d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a88ce501-d1c2-4f3a-8b39-416bb9fcdb64" xlink:to="loc_us-gaap_InterestExpense_50f34717-039a-4070-979b-d2e6a83de35d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_GainLossOnDerivativesAndOtherNonoperatingIncomeExpenseNet_9edae3cf-8958-4c54-a2ac-873329eb842a" xlink:href="nnbr-20220930.xsd#nnbr_GainLossOnDerivativesAndOtherNonoperatingIncomeExpenseNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a88ce501-d1c2-4f3a-8b39-416bb9fcdb64" xlink:to="loc_nnbr_GainLossOnDerivativesAndOtherNonoperatingIncomeExpenseNet_9edae3cf-8958-4c54-a2ac-873329eb842a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_80b2bcd0-a25b-45d7-b057-3d2ba2441da5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a88ce501-d1c2-4f3a-8b39-416bb9fcdb64" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_80b2bcd0-a25b-45d7-b057-3d2ba2441da5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_56612ce4-9c75-4585-958b-5808b4ff19e0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a88ce501-d1c2-4f3a-8b39-416bb9fcdb64" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_56612ce4-9c75-4585-958b-5808b4ff19e0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_2797fbf6-b7c0-436e-b84a-971b5973fa61" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_56612ce4-9c75-4585-958b-5808b4ff19e0" xlink:to="loc_srt_ConsolidationItemsAxis_2797fbf6-b7c0-436e-b84a-971b5973fa61" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_2797fbf6-b7c0-436e-b84a-971b5973fa61_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_2797fbf6-b7c0-436e-b84a-971b5973fa61" xlink:to="loc_srt_ConsolidationItemsDomain_2797fbf6-b7c0-436e-b84a-971b5973fa61_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_2d77399f-3cdd-4790-9b09-40c008ce4d49" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_2797fbf6-b7c0-436e-b84a-971b5973fa61" xlink:to="loc_srt_ConsolidationItemsDomain_2d77399f-3cdd-4790-9b09-40c008ce4d49" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_8b6a20a8-b5e9-4e19-84dd-bad97a89c40e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_2d77399f-3cdd-4790-9b09-40c008ce4d49" xlink:to="loc_us-gaap_OperatingSegmentsMember_8b6a20a8-b5e9-4e19-84dd-bad97a89c40e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_CorporateAndEliminationsMember_f39d0016-aaee-4f27-aa64-8ff02027f2f9" xlink:href="nnbr-20220930.xsd#nnbr_CorporateAndEliminationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_2d77399f-3cdd-4790-9b09-40c008ce4d49" xlink:to="loc_nnbr_CorporateAndEliminationsMember_f39d0016-aaee-4f27-aa64-8ff02027f2f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_e787d3c7-e5b8-46ed-b8b9-b52a0c487c92" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IntersegmentEliminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_2d77399f-3cdd-4790-9b09-40c008ce4d49" xlink:to="loc_us-gaap_IntersegmentEliminationMember_e787d3c7-e5b8-46ed-b8b9-b52a0c487c92" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_554035fd-5254-4db9-bb7f-e155a79ba41a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_56612ce4-9c75-4585-958b-5808b4ff19e0" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_554035fd-5254-4db9-bb7f-e155a79ba41a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_554035fd-5254-4db9-bb7f-e155a79ba41a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_554035fd-5254-4db9-bb7f-e155a79ba41a" xlink:to="loc_us-gaap_SegmentDomain_554035fd-5254-4db9-bb7f-e155a79ba41a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_33d26a8c-bd10-4a2f-8ee1-a513e787cf95" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_554035fd-5254-4db9-bb7f-e155a79ba41a" xlink:to="loc_us-gaap_SegmentDomain_33d26a8c-bd10-4a2f-8ee1-a513e787cf95" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_MobileSolutionsMember_319ea4c8-47a2-4e8a-9eb7-30154fc551bd" xlink:href="nnbr-20220930.xsd#nnbr_MobileSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_33d26a8c-bd10-4a2f-8ee1-a513e787cf95" xlink:to="loc_nnbr_MobileSolutionsMember_319ea4c8-47a2-4e8a-9eb7-30154fc551bd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_PowerSolutionsMember_99e871b5-b81a-4b7f-a121-7c1d353dc5fd" xlink:href="nnbr-20220930.xsd#nnbr_PowerSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_33d26a8c-bd10-4a2f-8ee1-a513e787cf95" xlink:to="loc_nnbr_PowerSolutionsMember_99e871b5-b81a-4b7f-a121-7c1d353dc5fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_1a5129fc-029c-493a-88d6-39e5b8a2e8bc" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_56612ce4-9c75-4585-958b-5808b4ff19e0" xlink:to="loc_srt_StatementGeographicalAxis_1a5129fc-029c-493a-88d6-39e5b8a2e8bc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_1a5129fc-029c-493a-88d6-39e5b8a2e8bc_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_1a5129fc-029c-493a-88d6-39e5b8a2e8bc" xlink:to="loc_srt_SegmentGeographicalDomain_1a5129fc-029c-493a-88d6-39e5b8a2e8bc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_a2bbc23b-2d8d-4e05-882f-86ec3ba82c6e" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_1a5129fc-029c-493a-88d6-39e5b8a2e8bc" xlink:to="loc_srt_SegmentGeographicalDomain_a2bbc23b-2d8d-4e05-882f-86ec3ba82c6e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_e1ae7697-bccb-4b23-beef-02393db853f7" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_a2bbc23b-2d8d-4e05-882f-86ec3ba82c6e" xlink:to="loc_country_US_e1ae7697-bccb-4b23-beef-02393db853f7" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/SegmentInformationAdditionalInformationDetails" xlink:type="simple" xlink:href="nnbr-20220930.xsd#SegmentInformationAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/SegmentInformationAdditionalInformationDetails" xlink:type="extended" id="i1577fd6f74944c0484cae6f03ed73433_SegmentInformationAdditionalInformationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7c5f22a3-8f07-48a7-957e-158438172c40" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EntityWideRevenueMajorCustomerLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_c1d7a81e-8446-45fd-98f0-a880d7bc7d70" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7c5f22a3-8f07-48a7-957e-158438172c40" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_c1d7a81e-8446-45fd-98f0-a880d7bc7d70" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_580bf9c6-4a84-4a96-a6d6-9a5543d65ad6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7c5f22a3-8f07-48a7-957e-158438172c40" xlink:to="loc_us-gaap_NumberOfReportableSegments_580bf9c6-4a84-4a96-a6d6-9a5543d65ad6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments_7c7706be-688d-44a3-ae1e-009fd84c0ea4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NumberOfOperatingSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7c5f22a3-8f07-48a7-957e-158438172c40" xlink:to="loc_us-gaap_NumberOfOperatingSegments_7c7706be-688d-44a3-ae1e-009fd84c0ea4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_81b023b4-127a-46c9-a337-f34ce8f42b26" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7c5f22a3-8f07-48a7-957e-158438172c40" xlink:to="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_81b023b4-127a-46c9-a337-f34ce8f42b26" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_17f388fb-693a-4510-a8a7-1d771a66dbb3" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_81b023b4-127a-46c9-a337-f34ce8f42b26" xlink:to="loc_srt_MajorCustomersAxis_17f388fb-693a-4510-a8a7-1d771a66dbb3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_17f388fb-693a-4510-a8a7-1d771a66dbb3_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_17f388fb-693a-4510-a8a7-1d771a66dbb3" xlink:to="loc_srt_NameOfMajorCustomerDomain_17f388fb-693a-4510-a8a7-1d771a66dbb3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_eae22ff4-3fdd-44bb-a55c-c9e597e8b5ed" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_17f388fb-693a-4510-a8a7-1d771a66dbb3" xlink:to="loc_srt_NameOfMajorCustomerDomain_eae22ff4-3fdd-44bb-a55c-c9e597e8b5ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_MajorCustomerMember_a3a5c3cc-dc46-4a90-87e0-8505d94d9f3b" xlink:href="nnbr-20220930.xsd#nnbr_MajorCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_eae22ff4-3fdd-44bb-a55c-c9e597e8b5ed" xlink:to="loc_nnbr_MajorCustomerMember_a3a5c3cc-dc46-4a90-87e0-8505d94d9f3b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d215f1e0-ec74-4287-9b33-054956038749" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_81b023b4-127a-46c9-a337-f34ce8f42b26" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d215f1e0-ec74-4287-9b33-054956038749" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_d215f1e0-ec74-4287-9b33-054956038749_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d215f1e0-ec74-4287-9b33-054956038749" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_d215f1e0-ec74-4287-9b33-054956038749_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_0a8bcb92-8238-4f83-9084-de6942ba670f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d215f1e0-ec74-4287-9b33-054956038749" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_0a8bcb92-8238-4f83-9084-de6942ba670f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableMember_4af9a41b-1a1e-4feb-b963-1778b7250320" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_0a8bcb92-8238-4f83-9084-de6942ba670f" xlink:to="loc_us-gaap_AccountsReceivableMember_4af9a41b-1a1e-4feb-b963-1778b7250320" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_f1c3af7f-9069-41ba-b127-b2ef76419385" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_81b023b4-127a-46c9-a337-f34ce8f42b26" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_f1c3af7f-9069-41ba-b127-b2ef76419385" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_f1c3af7f-9069-41ba-b127-b2ef76419385_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_f1c3af7f-9069-41ba-b127-b2ef76419385" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_f1c3af7f-9069-41ba-b127-b2ef76419385_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_9d46c97f-2e5f-4d0c-9cd6-201a6e3fa768" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_f1c3af7f-9069-41ba-b127-b2ef76419385" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_9d46c97f-2e5f-4d0c-9cd6-201a6e3fa768" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_e6fbb791-ce43-4854-a172-8569caf3d2e4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_9d46c97f-2e5f-4d0c-9cd6-201a6e3fa768" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_e6fbb791-ce43-4854-a172-8569caf3d2e4" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/IntangibleAssetsNetSummaryofCarryingAmountofIntangibleAssetsbySegmentDetail" xlink:type="simple" xlink:href="nnbr-20220930.xsd#IntangibleAssetsNetSummaryofCarryingAmountofIntangibleAssetsbySegmentDetail"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/IntangibleAssetsNetSummaryofCarryingAmountofIntangibleAssetsbySegmentDetail" xlink:type="extended" id="i32503ce3a2814c4ebb5e9af34ddcdd80_IntangibleAssetsNetSummaryofCarryingAmountofIntangibleAssetsbySegmentDetail">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_233a4d35-42b1-4f0a-a35a-d1125a357ec9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsRollForward_b694299d-d72b-43a7-9136-0a7e8b074533" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_233a4d35-42b1-4f0a-a35a-d1125a357ec9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsRollForward_b694299d-d72b-43a7-9136-0a7e8b074533" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_0077b96d-3963-4056-89c4-3fdf8957cce8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsRollForward_b694299d-d72b-43a7-9136-0a7e8b074533" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_0077b96d-3963-4056-89c4-3fdf8957cce8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_57fe86eb-1fcd-420e-9be2-d5773769202f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsRollForward_b694299d-d72b-43a7-9136-0a7e8b074533" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_57fe86eb-1fcd-420e-9be2-d5773769202f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_6cc8bd3f-9a71-42e6-b020-2d2946694489" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_a790b95b-78a1-46d6-901c-a697c715b8cd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_233a4d35-42b1-4f0a-a35a-d1125a357ec9" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_a790b95b-78a1-46d6-901c-a697c715b8cd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_3ef13d20-f466-480b-b4ca-27e0611a2abf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_a790b95b-78a1-46d6-901c-a697c715b8cd" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_3ef13d20-f466-480b-b4ca-27e0611a2abf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_3ef13d20-f466-480b-b4ca-27e0611a2abf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_3ef13d20-f466-480b-b4ca-27e0611a2abf" xlink:to="loc_us-gaap_SegmentDomain_3ef13d20-f466-480b-b4ca-27e0611a2abf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_446a449c-0583-49a3-a16b-d580a8396487" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_3ef13d20-f466-480b-b4ca-27e0611a2abf" xlink:to="loc_us-gaap_SegmentDomain_446a449c-0583-49a3-a16b-d580a8396487" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_MobileSolutionsMember_f73b9147-9cab-46d4-81ec-9768449fab37" xlink:href="nnbr-20220930.xsd#nnbr_MobileSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_446a449c-0583-49a3-a16b-d580a8396487" xlink:to="loc_nnbr_MobileSolutionsMember_f73b9147-9cab-46d4-81ec-9768449fab37" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_PowerSolutionsMember_4ceb638b-fdc3-405c-92ae-27acc946d9ba" xlink:href="nnbr-20220930.xsd#nnbr_PowerSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_446a449c-0583-49a3-a16b-d580a8396487" xlink:to="loc_nnbr_PowerSolutionsMember_4ceb638b-fdc3-405c-92ae-27acc946d9ba" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/InvestmentinJointVentureAdditionalInformationDetail" xlink:type="simple" xlink:href="nnbr-20220930.xsd#InvestmentinJointVentureAdditionalInformationDetail"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/InvestmentinJointVentureAdditionalInformationDetail" xlink:type="extended" id="ieba58d24a94949caa3c9a1df18147ba6_InvestmentinJointVentureAdditionalInformationDetail">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_59e269bc-c71b-4df7-91a1-82d8862e5e9e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_b291f5fb-2768-4c7b-95e0-80bae0b2e587" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_59e269bc-c71b-4df7-91a1-82d8862e5e9e" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_b291f5fb-2768-4c7b-95e0-80bae0b2e587" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_4b24350c-6643-4ff9-9e3a-b0c6e6deb5c4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_59e269bc-c71b-4df7-91a1-82d8862e5e9e" xlink:to="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_4b24350c-6643-4ff9-9e3a-b0c6e6deb5c4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_4e6669c6-6740-490a-b9b7-aba7614bfe84" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_4b24350c-6643-4ff9-9e3a-b0c6e6deb5c4" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_4e6669c6-6740-490a-b9b7-aba7614bfe84" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_4e6669c6-6740-490a-b9b7-aba7614bfe84_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_4e6669c6-6740-490a-b9b7-aba7614bfe84" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_4e6669c6-6740-490a-b9b7-aba7614bfe84_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_35ac32d3-3a28-44fd-9421-d59f9eb2ebee" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_4e6669c6-6740-490a-b9b7-aba7614bfe84" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_35ac32d3-3a28-44fd-9421-d59f9eb2ebee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_WuxiWeifuAutocamPrecisionMachineryCompanyLtdMember_05d6cf57-19d6-475b-a04d-2f46fb078817" xlink:href="nnbr-20220930.xsd#nnbr_WuxiWeifuAutocamPrecisionMachineryCompanyLtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_35ac32d3-3a28-44fd-9421-d59f9eb2ebee" xlink:to="loc_nnbr_WuxiWeifuAutocamPrecisionMachineryCompanyLtdMember_05d6cf57-19d6-475b-a04d-2f46fb078817" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/InvestmentinJointVentureSummarizedActivityRelatedtoInvestmentinJointVentureDetail" xlink:type="simple" xlink:href="nnbr-20220930.xsd#InvestmentinJointVentureSummarizedActivityRelatedtoInvestmentinJointVentureDetail"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/InvestmentinJointVentureSummarizedActivityRelatedtoInvestmentinJointVentureDetail" xlink:type="extended" id="if8265e1a080848ae9fe4db71aaa42158_InvestmentinJointVentureSummarizedActivityRelatedtoInvestmentinJointVentureDetail">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_e502d458-0ba0-46d0-8844-6d5821de43db" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_EquityMethodInvestmentsRollForward_1e99dbda-67fb-4d5a-bb41-42cf0816af46" xlink:href="nnbr-20220930.xsd#nnbr_EquityMethodInvestmentsRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_e502d458-0ba0-46d0-8844-6d5821de43db" xlink:to="loc_nnbr_EquityMethodInvestmentsRollForward_1e99dbda-67fb-4d5a-bb41-42cf0816af46" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_48f2e6fc-f17d-46e5-8e5f-f5cb44e0ca44" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_nnbr_EquityMethodInvestmentsRollForward_1e99dbda-67fb-4d5a-bb41-42cf0816af46" xlink:to="loc_us-gaap_EquityMethodInvestments_48f2e6fc-f17d-46e5-8e5f-f5cb44e0ca44" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_77eb6c48-95dc-415f-aae5-8a54d3e20815" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_nnbr_EquityMethodInvestmentsRollForward_1e99dbda-67fb-4d5a-bb41-42cf0816af46" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_77eb6c48-95dc-415f-aae5-8a54d3e20815" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentDividendsOrDistributions_99f61ef9-5b10-40e1-ba22-bc3f5a28c180" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestmentDividendsOrDistributions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_nnbr_EquityMethodInvestmentsRollForward_1e99dbda-67fb-4d5a-bb41-42cf0816af46" xlink:to="loc_us-gaap_EquityMethodInvestmentDividendsOrDistributions_99f61ef9-5b10-40e1-ba22-bc3f5a28c180" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_EquityMethodInvestmentForeignCurrencyTranslationGain_7e36848e-293f-4811-bcbf-04dd1e0759d4" xlink:href="nnbr-20220930.xsd#nnbr_EquityMethodInvestmentForeignCurrencyTranslationGain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_nnbr_EquityMethodInvestmentsRollForward_1e99dbda-67fb-4d5a-bb41-42cf0816af46" xlink:to="loc_nnbr_EquityMethodInvestmentForeignCurrencyTranslationGain_7e36848e-293f-4811-bcbf-04dd1e0759d4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_101788f5-bba0-4e46-9d24-280e15d09c60" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestments"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_fa6abf2d-4aa3-4367-96f7-b22b3c6960fe" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_e502d458-0ba0-46d0-8844-6d5821de43db" xlink:to="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_fa6abf2d-4aa3-4367-96f7-b22b3c6960fe" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_d569109f-c918-4fe3-909e-8a719b452165" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_fa6abf2d-4aa3-4367-96f7-b22b3c6960fe" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_d569109f-c918-4fe3-909e-8a719b452165" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_d569109f-c918-4fe3-909e-8a719b452165_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_d569109f-c918-4fe3-909e-8a719b452165" xlink:to="loc_us-gaap_RelatedPartyDomain_d569109f-c918-4fe3-909e-8a719b452165_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_43e97297-01d2-4d31-a9cf-51fcda2cdcbe" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_d569109f-c918-4fe3-909e-8a719b452165" xlink:to="loc_us-gaap_RelatedPartyDomain_43e97297-01d2-4d31-a9cf-51fcda2cdcbe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateJointVentureMember_caf71eaf-770c-4e46-a61a-fc9f3c2ed75e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CorporateJointVentureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_43e97297-01d2-4d31-a9cf-51fcda2cdcbe" xlink:to="loc_us-gaap_CorporateJointVentureMember_caf71eaf-770c-4e46-a61a-fc9f3c2ed75e" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/DebtAdditionalInformationDetail" xlink:type="simple" xlink:href="nnbr-20220930.xsd#DebtAdditionalInformationDetail"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/DebtAdditionalInformationDetail" xlink:type="extended" id="iec76b1339fe144e3b2310eefa35ed618_DebtAdditionalInformationDetail">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_0d865164-0af6-49de-a8f4-c554a0732812" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_0d865164-0af6-49de-a8f4-c554a0732812" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_ceba210c-a496-4555-bad2-a3b6b3c4208b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_ceba210c-a496-4555-bad2-a3b6b3c4208b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_5f862d41-4b81-4329-b6ac-70ad5b175d84" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_5f862d41-4b81-4329-b6ac-70ad5b175d84" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateDuringPeriod_6f73b19d-d090-43bf-a5ac-06f214769a70" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentInterestRateDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_DebtInstrumentInterestRateDuringPeriod_6f73b19d-d090-43bf-a5ac-06f214769a70" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_19d90687-b34d-4d2c-9173-fcefe8f7c69d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentPeriodicPaymentPrincipal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_19d90687-b34d-4d2c-9173-fcefe8f7c69d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_62c3e40f-cf05-4ef3-b6c2-b8b392bba585" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_62c3e40f-cf05-4ef3-b6c2-b8b392bba585" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsGross_be220eb7-2f46-435f-9d13-7a337b5b7452" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredFinanceCostsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_DeferredFinanceCostsGross_be220eb7-2f46-435f-9d13-7a337b5b7452" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_DebtInstrumentLIBORFloorRate_0f385037-b7cf-4913-a757-bc675d019c6a" xlink:href="nnbr-20220930.xsd#nnbr_DebtInstrumentLIBORFloorRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_nnbr_DebtInstrumentLIBORFloorRate_0f385037-b7cf-4913-a757-bc675d019c6a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_bf4e7623-f326-49bf-9a7d-9ba0464a7c7a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_bf4e7623-f326-49bf-9a7d-9ba0464a7c7a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansPayable_7164acdc-bc44-4b2d-939b-a2d6dd2b867d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LoansPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_LoansPayable_7164acdc-bc44-4b2d-939b-a2d6dd2b867d" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_1470bb60-781c-417c-84e0-b99fbc044600" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_1470bb60-781c-417c-84e0-b99fbc044600" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_846192cd-d2f6-401d-8a05-1a6108139a41" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_846192cd-d2f6-401d-8a05-1a6108139a41" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromLinesOfCredit_e354a582-a0e7-4af8-9a23-e61ce14de9c4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromLinesOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_ProceedsFromLinesOfCredit_e354a582-a0e7-4af8-9a23-e61ce14de9c4" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet_32bb41ee-42b1-4767-80f2-faec30ed75fa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet_32bb41ee-42b1-4767-80f2-faec30ed75fa" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestCostsCapitalized_1e7c9ed7-e351-4fd3-83c2-dd6860e5eec5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestCostsCapitalized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_InterestCostsCapitalized_1e7c9ed7-e351-4fd3-83c2-dd6860e5eec5" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_95594060-00b9-4a1e-8d36-8c315213f48e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_95594060-00b9-4a1e-8d36-8c315213f48e" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFixedInterestRate_8d3c6469-8b14-4fb7-8d33-5ff598a2709d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeFixedInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_DerivativeFixedInterestRate_8d3c6469-8b14-4fb7-8d33-5ff598a2709d" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_7ca17f37-8a06-4941-ade1-05756107a0e1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_DerivativeNotionalAmount_7ca17f37-8a06-4941-ade1-05756107a0e1" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_9dd603a4-129c-4b32-bb6a-7836d0560f0d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1dd3be63-e32d-4f2e-8b98-994c3f04525d" xlink:to="loc_us-gaap_DebtInstrumentTable_9dd603a4-129c-4b32-bb6a-7836d0560f0d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_fd302d8f-4cf6-43c7-85fb-5a6e53a1bb12" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9dd603a4-129c-4b32-bb6a-7836d0560f0d" xlink:to="loc_us-gaap_CreditFacilityAxis_fd302d8f-4cf6-43c7-85fb-5a6e53a1bb12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_fd302d8f-4cf6-43c7-85fb-5a6e53a1bb12_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_fd302d8f-4cf6-43c7-85fb-5a6e53a1bb12" xlink:to="loc_us-gaap_CreditFacilityDomain_fd302d8f-4cf6-43c7-85fb-5a6e53a1bb12_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_eadbb2e9-c9d3-48e7-a353-ea91ea4de401" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_fd302d8f-4cf6-43c7-85fb-5a6e53a1bb12" xlink:to="loc_us-gaap_CreditFacilityDomain_eadbb2e9-c9d3-48e7-a353-ea91ea4de401" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_TermLoanFacilityMemberMember_0f1bfd59-6cd6-46bd-b7ce-6e0ef1a87650" xlink:href="nnbr-20220930.xsd#nnbr_TermLoanFacilityMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_eadbb2e9-c9d3-48e7-a353-ea91ea4de401" xlink:to="loc_nnbr_TermLoanFacilityMemberMember_0f1bfd59-6cd6-46bd-b7ce-6e0ef1a87650" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_AssetBackedCreditFacilityMemberMember_bacbf871-eaa7-4c60-acbe-0239a7683ea9" xlink:href="nnbr-20220930.xsd#nnbr_AssetBackedCreditFacilityMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_eadbb2e9-c9d3-48e7-a353-ea91ea4de401" xlink:to="loc_nnbr_AssetBackedCreditFacilityMemberMember_bacbf871-eaa7-4c60-acbe-0239a7683ea9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_SeniorSecuredRevolvingFacilityMember_db0e7fd6-98d9-4f77-a0f7-e556fed04942" xlink:href="nnbr-20220930.xsd#nnbr_SeniorSecuredRevolvingFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_eadbb2e9-c9d3-48e7-a353-ea91ea4de401" xlink:to="loc_nnbr_SeniorSecuredRevolvingFacilityMember_db0e7fd6-98d9-4f77-a0f7-e556fed04942" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LetterOfCreditMember_fb685fc0-e2c6-4623-b683-86c18a989da0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LetterOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_eadbb2e9-c9d3-48e7-a353-ea91ea4de401" xlink:to="loc_us-gaap_LetterOfCreditMember_fb685fc0-e2c6-4623-b683-86c18a989da0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BridgeLoanMember_d1959106-85a6-47b1-87bd-39106374777f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BridgeLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_eadbb2e9-c9d3-48e7-a353-ea91ea4de401" xlink:to="loc_us-gaap_BridgeLoanMember_d1959106-85a6-47b1-87bd-39106374777f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_3b01e3b2-3370-4c0b-a921-32f6dcc19695" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9dd603a4-129c-4b32-bb6a-7836d0560f0d" xlink:to="loc_us-gaap_VariableRateAxis_3b01e3b2-3370-4c0b-a921-32f6dcc19695" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_3b01e3b2-3370-4c0b-a921-32f6dcc19695_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_3b01e3b2-3370-4c0b-a921-32f6dcc19695" xlink:to="loc_us-gaap_VariableRateDomain_3b01e3b2-3370-4c0b-a921-32f6dcc19695_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_401e988a-349b-412f-86d8-4021e77c7bce" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_3b01e3b2-3370-4c0b-a921-32f6dcc19695" xlink:to="loc_us-gaap_VariableRateDomain_401e988a-349b-412f-86d8-4021e77c7bce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_1a7b477c-ee44-497c-913d-958442d0c34a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_401e988a-349b-412f-86d8-4021e77c7bce" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_1a7b477c-ee44-497c-913d-958442d0c34a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_VariousBenchmarkRatesMember_27ca56d3-1733-492c-8b84-edc6527e48e7" xlink:href="nnbr-20220930.xsd#nnbr_VariousBenchmarkRatesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_401e988a-349b-412f-86d8-4021e77c7bce" xlink:to="loc_nnbr_VariousBenchmarkRatesMember_27ca56d3-1733-492c-8b84-edc6527e48e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_FederalFundsOrPrimeRateMember_55c719d3-0e3b-4844-90b6-da6206cceb10" xlink:href="nnbr-20220930.xsd#nnbr_FederalFundsOrPrimeRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_401e988a-349b-412f-86d8-4021e77c7bce" xlink:to="loc_nnbr_FederalFundsOrPrimeRateMember_55c719d3-0e3b-4844-90b6-da6206cceb10" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrimeRateMember_4636435d-19f3-4a49-90bf-c97747a90d81" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PrimeRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_401e988a-349b-412f-86d8-4021e77c7bce" xlink:to="loc_us-gaap_PrimeRateMember_4636435d-19f3-4a49-90bf-c97747a90d81" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_VariousBenchmarkRatesMemberMember_2fc05aea-67cf-40df-a509-36bd2e46acad" xlink:href="nnbr-20220930.xsd#nnbr_VariousBenchmarkRatesMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_401e988a-349b-412f-86d8-4021e77c7bce" xlink:to="loc_nnbr_VariousBenchmarkRatesMemberMember_2fc05aea-67cf-40df-a509-36bd2e46acad" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_FederalFundsOrPrimeRateMemberMember_bbc9f8cf-773e-4bd3-84e7-fed0a0f2aa06" xlink:href="nnbr-20220930.xsd#nnbr_FederalFundsOrPrimeRateMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_401e988a-349b-412f-86d8-4021e77c7bce" xlink:to="loc_nnbr_FederalFundsOrPrimeRateMemberMember_bbc9f8cf-773e-4bd3-84e7-fed0a0f2aa06" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_6ba1904e-7546-469c-a97a-4193a75ac146" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9dd603a4-129c-4b32-bb6a-7836d0560f0d" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_6ba1904e-7546-469c-a97a-4193a75ac146" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_6ba1904e-7546-469c-a97a-4193a75ac146_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_6ba1904e-7546-469c-a97a-4193a75ac146" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_6ba1904e-7546-469c-a97a-4193a75ac146_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_1867628c-0340-43b0-9111-7a3e296aa958" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_6ba1904e-7546-469c-a97a-4193a75ac146" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_1867628c-0340-43b0-9111-7a3e296aa958" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_583f19f0-d480-4aeb-afee-ff95e08ef607" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_1867628c-0340-43b0-9111-7a3e296aa958" xlink:to="loc_us-gaap_InterestRateSwapMember_583f19f0-d480-4aeb-afee-ff95e08ef607" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_e0ea1aeb-d2ca-4a05-8c7b-c95204c2cedd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9dd603a4-129c-4b32-bb6a-7836d0560f0d" xlink:to="loc_us-gaap_FinancialInstrumentAxis_e0ea1aeb-d2ca-4a05-8c7b-c95204c2cedd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e0ea1aeb-d2ca-4a05-8c7b-c95204c2cedd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_e0ea1aeb-d2ca-4a05-8c7b-c95204c2cedd" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e0ea1aeb-d2ca-4a05-8c7b-c95204c2cedd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_80c6bc03-2f31-42ee-b2bd-6c56bb78e7d8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_e0ea1aeb-d2ca-4a05-8c7b-c95204c2cedd" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_80c6bc03-2f31-42ee-b2bd-6c56bb78e7d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_July222021Member_15e196bc-f97d-4daa-91fd-406980422266" xlink:href="nnbr-20220930.xsd#nnbr_July222021Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_80c6bc03-2f31-42ee-b2bd-6c56bb78e7d8" xlink:to="loc_nnbr_July222021Member_15e196bc-f97d-4daa-91fd-406980422266" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_February82019Member_cd159323-4c94-4c15-a8b3-ded4cdc9628a" xlink:href="nnbr-20220930.xsd#nnbr_February82019Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_80c6bc03-2f31-42ee-b2bd-6c56bb78e7d8" xlink:to="loc_nnbr_February82019Member_cd159323-4c94-4c15-a8b3-ded4cdc9628a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_1dfe9993-2513-4cbb-92f7-24f50feaeb5f" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9dd603a4-129c-4b32-bb6a-7836d0560f0d" xlink:to="loc_srt_RangeAxis_1dfe9993-2513-4cbb-92f7-24f50feaeb5f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_1dfe9993-2513-4cbb-92f7-24f50feaeb5f_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_1dfe9993-2513-4cbb-92f7-24f50feaeb5f" xlink:to="loc_srt_RangeMember_1dfe9993-2513-4cbb-92f7-24f50feaeb5f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_fd926b41-9103-46bf-8c40-08ab011f35c8" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_1dfe9993-2513-4cbb-92f7-24f50feaeb5f" xlink:to="loc_srt_RangeMember_fd926b41-9103-46bf-8c40-08ab011f35c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_c4e140fc-14b2-48ea-9372-2874d6ed5b60" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_fd926b41-9103-46bf-8c40-08ab011f35c8" xlink:to="loc_srt_MinimumMember_c4e140fc-14b2-48ea-9372-2874d6ed5b60" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_802c9176-0d1c-4915-94dc-9aa3fec4291d" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_fd926b41-9103-46bf-8c40-08ab011f35c8" xlink:to="loc_srt_MaximumMember_802c9176-0d1c-4915-94dc-9aa3fec4291d" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/DebtSummaryofDebtDetail" xlink:type="simple" xlink:href="nnbr-20220930.xsd#DebtSummaryofDebtDetail"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/DebtSummaryofDebtDetail" xlink:type="extended" id="i82d0d0caad4b4073827a29b9395f7e17_DebtSummaryofDebtDetail">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_ddfaed98-6c63-4fbd-834e-e9948c305de1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansPayable_e9d0abec-2f09-4d41-961c-20ef8bd03b44" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LoansPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddfaed98-6c63-4fbd-834e-e9948c305de1" xlink:to="loc_us-gaap_LoansPayable_e9d0abec-2f09-4d41-961c-20ef8bd03b44" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_9b2f4cd7-7dcf-4176-b7c7-784a44dffa4f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddfaed98-6c63-4fbd-834e-e9948c305de1" xlink:to="loc_us-gaap_LineOfCredit_9b2f4cd7-7dcf-4176-b7c7-784a44dffa4f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_60ca047a-8765-417e-a717-f1132abb5e75" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddfaed98-6c63-4fbd-834e-e9948c305de1" xlink:to="loc_us-gaap_LongTermDebt_60ca047a-8765-417e-a717-f1132abb5e75" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_0b99dc4d-1bf8-4638-b8b5-243b9c8b680a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddfaed98-6c63-4fbd-834e-e9948c305de1" xlink:to="loc_us-gaap_LongTermDebtCurrent_0b99dc4d-1bf8-4638-b8b5-243b9c8b680a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_ec853d10-30c3-4364-8e3f-35264515929a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddfaed98-6c63-4fbd-834e-e9948c305de1" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_ec853d10-30c3-4364-8e3f-35264515929a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnamortizedDebtIssuanceExpense_d01200a8-c6fd-4b8a-b99f-78f9b60a6840" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UnamortizedDebtIssuanceExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddfaed98-6c63-4fbd-834e-e9948c305de1" xlink:to="loc_us-gaap_UnamortizedDebtIssuanceExpense_d01200a8-c6fd-4b8a-b99f-78f9b60a6840" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_358a62a8-12b9-4367-951b-e5f69e259952" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddfaed98-6c63-4fbd-834e-e9948c305de1" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_358a62a8-12b9-4367-951b-e5f69e259952" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet_996b88cb-3432-4bd0-8e3a-71c4082e8bbc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddfaed98-6c63-4fbd-834e-e9948c305de1" xlink:to="loc_us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet_996b88cb-3432-4bd0-8e3a-71c4082e8bbc" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_1477bfbc-37a7-4813-8712-ae1e752ee019" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddfaed98-6c63-4fbd-834e-e9948c305de1" xlink:to="loc_us-gaap_DebtInstrumentTable_1477bfbc-37a7-4813-8712-ae1e752ee019" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_fbd971b6-face-4417-b579-beb1516ab0a2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_1477bfbc-37a7-4813-8712-ae1e752ee019" xlink:to="loc_us-gaap_DebtInstrumentAxis_fbd971b6-face-4417-b579-beb1516ab0a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_fbd971b6-face-4417-b579-beb1516ab0a2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_fbd971b6-face-4417-b579-beb1516ab0a2" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_fbd971b6-face-4417-b579-beb1516ab0a2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_8146f3d2-2b51-4ad5-9805-010c49bf3ca9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_fbd971b6-face-4417-b579-beb1516ab0a2" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_8146f3d2-2b51-4ad5-9805-010c49bf3ca9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignLineOfCreditMember_42327c66-f1c6-434b-a81e-2a24dda54ec5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignLineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_8146f3d2-2b51-4ad5-9805-010c49bf3ca9" xlink:to="loc_us-gaap_ForeignLineOfCreditMember_42327c66-f1c6-434b-a81e-2a24dda54ec5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_434828cc-0c1d-4848-a8b1-628d69d033b0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_1477bfbc-37a7-4813-8712-ae1e752ee019" xlink:to="loc_us-gaap_CreditFacilityAxis_434828cc-0c1d-4848-a8b1-628d69d033b0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_434828cc-0c1d-4848-a8b1-628d69d033b0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_434828cc-0c1d-4848-a8b1-628d69d033b0" xlink:to="loc_us-gaap_CreditFacilityDomain_434828cc-0c1d-4848-a8b1-628d69d033b0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_991660b6-33db-4228-86fa-b38f4aa52be6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_434828cc-0c1d-4848-a8b1-628d69d033b0" xlink:to="loc_us-gaap_CreditFacilityDomain_991660b6-33db-4228-86fa-b38f4aa52be6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_TermLoanFacilityMemberMember_66b84c74-9572-4c92-92bf-0360e780a297" xlink:href="nnbr-20220930.xsd#nnbr_TermLoanFacilityMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_991660b6-33db-4228-86fa-b38f4aa52be6" xlink:to="loc_nnbr_TermLoanFacilityMemberMember_66b84c74-9572-4c92-92bf-0360e780a297" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/CommitmentsandContingenciesAdditionalInformationDetail" xlink:type="simple" xlink:href="nnbr-20220930.xsd#CommitmentsandContingenciesAdditionalInformationDetail"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/CommitmentsandContingenciesAdditionalInformationDetail" xlink:type="extended" id="i54f57a37d9c54c9cb061c92180642675_CommitmentsandContingenciesAdditionalInformationDetail">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_1b7f68da-b695-418a-b793-73bd270eef89" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_8d2f7151-9322-4052-895a-35f3342d3682" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingencyEstimateOfPossibleLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_1b7f68da-b695-418a-b793-73bd270eef89" xlink:to="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_8d2f7151-9322-4052-895a-35f3342d3682" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_16905120-409b-4ae5-a2ba-6433cc7b6d85" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_1b7f68da-b695-418a-b793-73bd270eef89" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_16905120-409b-4ae5-a2ba-6433cc7b6d85" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationSettlementAmountAwardedToOtherParty_602f6197-d8ce-42c8-b26a-fe330c3b18fa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LitigationSettlementAmountAwardedToOtherParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_1b7f68da-b695-418a-b793-73bd270eef89" xlink:to="loc_us-gaap_LitigationSettlementAmountAwardedToOtherParty_602f6197-d8ce-42c8-b26a-fe330c3b18fa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationSettlementExpense_f61dfeef-bdd9-4fb6-ba89-9f0c177b3b13" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LitigationSettlementExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_1b7f68da-b695-418a-b793-73bd270eef89" xlink:to="loc_us-gaap_LitigationSettlementExpense_f61dfeef-bdd9-4fb6-ba89-9f0c177b3b13" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_2e5b9ead-6fe3-4785-aeec-3761c685e57e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_1b7f68da-b695-418a-b793-73bd270eef89" xlink:to="loc_us-gaap_LossContingenciesTable_2e5b9ead-6fe3-4785-aeec-3761c685e57e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_4ffe98cc-f99c-4162-9d91-966588be3ac9" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_2e5b9ead-6fe3-4785-aeec-3761c685e57e" xlink:to="loc_srt_RangeAxis_4ffe98cc-f99c-4162-9d91-966588be3ac9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_4ffe98cc-f99c-4162-9d91-966588be3ac9_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_4ffe98cc-f99c-4162-9d91-966588be3ac9" xlink:to="loc_srt_RangeMember_4ffe98cc-f99c-4162-9d91-966588be3ac9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_9c48d42d-fb6d-4938-99a9-376ef865ce92" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_4ffe98cc-f99c-4162-9d91-966588be3ac9" xlink:to="loc_srt_RangeMember_9c48d42d-fb6d-4938-99a9-376ef865ce92" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_24e9f2bd-40c8-4898-a571-c03e3c89ff2b" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_9c48d42d-fb6d-4938-99a9-376ef865ce92" xlink:to="loc_srt_MaximumMember_24e9f2bd-40c8-4898-a571-c03e3c89ff2b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseAxis_da19c398-a412-4b29-a5ba-5a99494ec2f7" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_LitigationCaseAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_2e5b9ead-6fe3-4785-aeec-3761c685e57e" xlink:to="loc_srt_LitigationCaseAxis_da19c398-a412-4b29-a5ba-5a99494ec2f7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_da19c398-a412-4b29-a5ba-5a99494ec2f7_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_LitigationCaseAxis_da19c398-a412-4b29-a5ba-5a99494ec2f7" xlink:to="loc_srt_LitigationCaseTypeDomain_da19c398-a412-4b29-a5ba-5a99494ec2f7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_489f5dba-ca15-401d-80cc-9b9419b109bb" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_LitigationCaseAxis_da19c398-a412-4b29-a5ba-5a99494ec2f7" xlink:to="loc_srt_LitigationCaseTypeDomain_489f5dba-ca15-401d-80cc-9b9419b109bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_TaxMatterMember_3825b4a1-aed1-4d62-ab35-9eb248b7d3cb" xlink:href="nnbr-20220930.xsd#nnbr_TaxMatterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_489f5dba-ca15-401d-80cc-9b9419b109bb" xlink:to="loc_nnbr_TaxMatterMember_3825b4a1-aed1-4d62-ab35-9eb248b7d3cb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_SecuritiesOfferingMatterMember_4976a870-a343-4ae8-8e7f-dcf2cbd3f7f1" xlink:href="nnbr-20220930.xsd#nnbr_SecuritiesOfferingMatterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_489f5dba-ca15-401d-80cc-9b9419b109bb" xlink:to="loc_nnbr_SecuritiesOfferingMatterMember_4976a870-a343-4ae8-8e7f-dcf2cbd3f7f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_ContractClaimsMember_e72918e3-5221-4ecd-a560-f1853d5a6dab" xlink:href="nnbr-20220930.xsd#nnbr_ContractClaimsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_489f5dba-ca15-401d-80cc-9b9419b109bb" xlink:to="loc_nnbr_ContractClaimsMember_e72918e3-5221-4ecd-a560-f1853d5a6dab" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/PreferredStockandStockholdersEquityAdditionalInformationDetails" xlink:type="simple" xlink:href="nnbr-20220930.xsd#PreferredStockandStockholdersEquityAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/PreferredStockandStockholdersEquityAdditionalInformationDetails" xlink:type="extended" id="i8ece344e69544048b7dc93db59d41bb5_PreferredStockandStockholdersEquityAdditionalInformationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_8714eb35-44a6-4935-abbf-273f3af538e1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_8714eb35-44a6-4935-abbf-273f3af538e1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityParOrStatedValuePerShare_5ef77f8b-29f5-4f05-9769-f471b3647c76" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:to="loc_us-gaap_TemporaryEquityParOrStatedValuePerShare_5ef77f8b-29f5-4f05-9769-f471b3647c76" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_ba1468ec-479f-46aa-b55e-755a5e7b98d8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_ba1468ec-479f-46aa-b55e-755a5e7b98d8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_adef9f99-0d09-4843-996e-2b60763d7e39" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:to="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_adef9f99-0d09-4843-996e-2b60763d7e39" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_c2c201ed-9542-44da-9e79-af0ac94294cd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_c2c201ed-9542-44da-9e79-af0ac94294cd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityLiquidationPreferencePerShare_ec12ecf6-88f4-4ab8-b80b-d7d7665c517c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityLiquidationPreferencePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:to="loc_us-gaap_TemporaryEquityLiquidationPreferencePerShare_ec12ecf6-88f4-4ab8-b80b-d7d7665c517c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_TemporaryEquityDividendRatePercentage_05b0ca31-7bb1-4360-a5ab-d5bb79fc6730" xlink:href="nnbr-20220930.xsd#nnbr_TemporaryEquityDividendRatePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:to="loc_nnbr_TemporaryEquityDividendRatePercentage_05b0ca31-7bb1-4360-a5ab-d5bb79fc6730" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_TemporaryEquityDividendRatePercentageIncreaseIfNoDividendPaid_f41f2a7d-e63d-42e8-9ce5-6bc8599c2cdc" xlink:href="nnbr-20220930.xsd#nnbr_TemporaryEquityDividendRatePercentageIncreaseIfNoDividendPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:to="loc_nnbr_TemporaryEquityDividendRatePercentageIncreaseIfNoDividendPaid_f41f2a7d-e63d-42e8-9ce5-6bc8599c2cdc" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_TemporaryEquityDividendRatePercentageAnnualIncrease_8c949a15-62e4-4640-8980-ced1f9674e3b" xlink:href="nnbr-20220930.xsd#nnbr_TemporaryEquityDividendRatePercentageAnnualIncrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:to="loc_nnbr_TemporaryEquityDividendRatePercentageAnnualIncrease_8c949a15-62e4-4640-8980-ced1f9674e3b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests_8352427e-c4b5-4fe3-84b3-c1c2bb1dd904" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:to="loc_us-gaap_TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests_8352427e-c4b5-4fe3-84b3-c1c2bb1dd904" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityDividendsAdjustment_217e95ec-32b1-4775-827c-34463657293d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityDividendsAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:to="loc_us-gaap_TemporaryEquityDividendsAdjustment_217e95ec-32b1-4775-827c-34463657293d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight_cfaba8b6-ae6f-4bfc-8e58-f9209ec729e9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:to="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight_cfaba8b6-ae6f-4bfc-8e58-f9209ec729e9" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_TemporaryEquityDividendsUnpaidDeemed_5e1afe2f-3edf-4c98-b106-44595af17a0a" xlink:href="nnbr-20220930.xsd#nnbr_TemporaryEquityDividendsUnpaidDeemed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:to="loc_nnbr_TemporaryEquityDividendsUnpaidDeemed_5e1afe2f-3edf-4c98-b106-44595af17a0a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityAggregateAmountOfRedemptionRequirement_4aef89e3-e660-4ddc-a8bd-fcb10b1623c5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityAggregateAmountOfRedemptionRequirement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:to="loc_us-gaap_TemporaryEquityAggregateAmountOfRedemptionRequirement_4aef89e3-e660-4ddc-a8bd-fcb10b1623c5" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityByClassOfStockTable_31ec336e-0c28-41cb-ac4a-301ac3bc303d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityByClassOfStockTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_TemporaryEquityLineItems_eff4e418-2e0a-45c2-b8a6-8835d7b80c7f" xlink:to="loc_us-gaap_TemporaryEquityByClassOfStockTable_31ec336e-0c28-41cb-ac4a-301ac3bc303d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_2a50181c-95e6-4158-a0a9-ae9cd4c11236" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_TemporaryEquityByClassOfStockTable_31ec336e-0c28-41cb-ac4a-301ac3bc303d" xlink:to="loc_us-gaap_StatementClassOfStockAxis_2a50181c-95e6-4158-a0a9-ae9cd4c11236" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_2a50181c-95e6-4158-a0a9-ae9cd4c11236_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2a50181c-95e6-4158-a0a9-ae9cd4c11236" xlink:to="loc_us-gaap_ClassOfStockDomain_2a50181c-95e6-4158-a0a9-ae9cd4c11236_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_f939c7c7-48c8-4a22-b393-c9981cead2d8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2a50181c-95e6-4158-a0a9-ae9cd4c11236" xlink:to="loc_us-gaap_ClassOfStockDomain_f939c7c7-48c8-4a22-b393-c9981cead2d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesDPreferredStockMember_13907a64-3117-4b2d-a64b-212c72769027" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeriesDPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_f939c7c7-48c8-4a22-b393-c9981cead2d8" xlink:to="loc_us-gaap_SeriesDPreferredStockMember_13907a64-3117-4b2d-a64b-212c72769027" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesBPreferredStockMember_8885234d-49c6-4aae-b0b7-10e09e6be2ff" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeriesBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_f939c7c7-48c8-4a22-b393-c9981cead2d8" xlink:to="loc_us-gaap_SeriesBPreferredStockMember_8885234d-49c6-4aae-b0b7-10e09e6be2ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightAxis_a2de2a40-5bab-4e19-9eed-6330214e3cde" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_TemporaryEquityByClassOfStockTable_31ec336e-0c28-41cb-ac4a-301ac3bc303d" xlink:to="loc_us-gaap_ClassOfWarrantOrRightAxis_a2de2a40-5bab-4e19-9eed-6330214e3cde" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_a2de2a40-5bab-4e19-9eed-6330214e3cde_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_a2de2a40-5bab-4e19-9eed-6330214e3cde" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_a2de2a40-5bab-4e19-9eed-6330214e3cde_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_7f6bdf1e-667d-4536-ab94-4c9ded17664f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_a2de2a40-5bab-4e19-9eed-6330214e3cde" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_7f6bdf1e-667d-4536-ab94-4c9ded17664f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesCPreferredStockMember_fce67627-7859-43c9-8218-ac5ff654b7db" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeriesCPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_7f6bdf1e-667d-4536-ab94-4c9ded17664f" xlink:to="loc_us-gaap_SeriesCPreferredStockMember_fce67627-7859-43c9-8218-ac5ff654b7db" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_5b7a46dd-94d8-494f-9a0d-2383c2577453" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_TemporaryEquityByClassOfStockTable_31ec336e-0c28-41cb-ac4a-301ac3bc303d" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_5b7a46dd-94d8-494f-9a0d-2383c2577453" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_5b7a46dd-94d8-494f-9a0d-2383c2577453_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_5b7a46dd-94d8-494f-9a0d-2383c2577453" xlink:to="loc_us-gaap_EquityComponentDomain_5b7a46dd-94d8-494f-9a0d-2383c2577453_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_88ae7993-c644-4138-ad14-5d0447c79ef8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_5b7a46dd-94d8-494f-9a0d-2383c2577453" xlink:to="loc_us-gaap_EquityComponentDomain_88ae7993-c644-4138-ad14-5d0447c79ef8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_ead47fbe-24a4-458c-81bf-24a03e8a2232" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_88ae7993-c644-4138-ad14-5d0447c79ef8" xlink:to="loc_us-gaap_CommonStockMember_ead47fbe-24a4-458c-81bf-24a03e8a2232" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_561e8fe2-8bca-4f98-8a45-57bb6acc6613" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_TemporaryEquityByClassOfStockTable_31ec336e-0c28-41cb-ac4a-301ac3bc303d" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_561e8fe2-8bca-4f98-8a45-57bb6acc6613" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_561e8fe2-8bca-4f98-8a45-57bb6acc6613_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_561e8fe2-8bca-4f98-8a45-57bb6acc6613" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_561e8fe2-8bca-4f98-8a45-57bb6acc6613_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_207c8486-e6a1-45f9-b7c9-107778eb9876" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_561e8fe2-8bca-4f98-8a45-57bb6acc6613" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_207c8486-e6a1-45f9-b7c9-107778eb9876" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrivatePlacementMember_9bdb602c-693e-4796-87fc-ae68b940e19b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PrivatePlacementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_207c8486-e6a1-45f9-b7c9-107778eb9876" xlink:to="loc_us-gaap_PrivatePlacementMember_9bdb602c-693e-4796-87fc-ae68b940e19b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementScenarioAxis_23333be5-00b6-42b1-991e-bd73698e585d" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_StatementScenarioAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_TemporaryEquityByClassOfStockTable_31ec336e-0c28-41cb-ac4a-301ac3bc303d" xlink:to="loc_srt_StatementScenarioAxis_23333be5-00b6-42b1-991e-bd73698e585d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_23333be5-00b6-42b1-991e-bd73698e585d_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementScenarioAxis_23333be5-00b6-42b1-991e-bd73698e585d" xlink:to="loc_srt_ScenarioUnspecifiedDomain_23333be5-00b6-42b1-991e-bd73698e585d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_4c180240-f0af-431b-86f0-92060ad93a61" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementScenarioAxis_23333be5-00b6-42b1-991e-bd73698e585d" xlink:to="loc_srt_ScenarioUnspecifiedDomain_4c180240-f0af-431b-86f0-92060ad93a61" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioForecastMember_31d37c89-fbde-4d3f-b208-bffb9fe41a97" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ScenarioForecastMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ScenarioUnspecifiedDomain_4c180240-f0af-431b-86f0-92060ad93a61" xlink:to="loc_srt_ScenarioForecastMember_31d37c89-fbde-4d3f-b208-bffb9fe41a97" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/PreferredStockandStockholdersEquityCarryingValueRollForwardDetails" xlink:type="simple" xlink:href="nnbr-20220930.xsd#PreferredStockandStockholdersEquityCarryingValueRollForwardDetails"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/PreferredStockandStockholdersEquityCarryingValueRollForwardDetails" xlink:type="extended" id="i57f309adb76f445ca5a73d277ff765b8_PreferredStockandStockholdersEquityCarryingValueRollForwardDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityLineItems_990de762-a597-47b3-90ae-e57fb7cdd7f9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_091ce7d2-9b77-492e-a89b-ad3f8792de4b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInTemporaryEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityLineItems_990de762-a597-47b3-90ae-e57fb7cdd7f9" xlink:to="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_091ce7d2-9b77-492e-a89b-ad3f8792de4b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_ffcb88e5-08e1-45ec-8d92-79032114f64b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_091ce7d2-9b77-492e-a89b-ad3f8792de4b" xlink:to="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_ffcb88e5-08e1-45ec-8d92-79032114f64b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues_d8a85a3d-239b-4a7c-b59c-00031b6f4417" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_091ce7d2-9b77-492e-a89b-ad3f8792de4b" xlink:to="loc_us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues_d8a85a3d-239b-4a7c-b59c-00031b6f4417" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_TemporaryEquityFairValueOfWarrantsIssued_df08a3a6-2278-46a7-a5e1-4668f79d3c06" xlink:href="nnbr-20220930.xsd#nnbr_TemporaryEquityFairValueOfWarrantsIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_091ce7d2-9b77-492e-a89b-ad3f8792de4b" xlink:to="loc_nnbr_TemporaryEquityFairValueOfWarrantsIssued_df08a3a6-2278-46a7-a5e1-4668f79d3c06" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_TemporaryEquityRecognitionOfBifurcatedEmbeddedDerivative_31b00ee4-7fcd-487d-ba7d-f181b64cad90" xlink:href="nnbr-20220930.xsd#nnbr_TemporaryEquityRecognitionOfBifurcatedEmbeddedDerivative"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_091ce7d2-9b77-492e-a89b-ad3f8792de4b" xlink:to="loc_nnbr_TemporaryEquityRecognitionOfBifurcatedEmbeddedDerivative_31b00ee4-7fcd-487d-ba7d-f181b64cad90" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityDividendsAdjustment_bf25621c-e70c-4dff-ac1e-3de501a78d22" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityDividendsAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_091ce7d2-9b77-492e-a89b-ad3f8792de4b" xlink:to="loc_us-gaap_TemporaryEquityDividendsAdjustment_bf25621c-e70c-4dff-ac1e-3de501a78d22" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityOtherChanges_3dc9ab9b-fb96-422e-ab90-2bcc02a216a3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityOtherChanges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_091ce7d2-9b77-492e-a89b-ad3f8792de4b" xlink:to="loc_us-gaap_TemporaryEquityOtherChanges_3dc9ab9b-fb96-422e-ab90-2bcc02a216a3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_TemporaryEquityRedemption_636c20a5-ac7c-4ad0-a7b9-7b13a822252b" xlink:href="nnbr-20220930.xsd#nnbr_TemporaryEquityRedemption"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_091ce7d2-9b77-492e-a89b-ad3f8792de4b" xlink:to="loc_nnbr_TemporaryEquityRedemption_636c20a5-ac7c-4ad0-a7b9-7b13a822252b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_7737a11f-e4c7-4ab5-8600-ec7fdb5d5f09" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityByClassOfStockTable_ef61056e-48b6-4b32-9f29-47c1aa1cca66" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityByClassOfStockTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_TemporaryEquityLineItems_990de762-a597-47b3-90ae-e57fb7cdd7f9" xlink:to="loc_us-gaap_TemporaryEquityByClassOfStockTable_ef61056e-48b6-4b32-9f29-47c1aa1cca66" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_d3b17bd7-25f1-41f8-9d6f-b007bd7b8d30" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_TemporaryEquityByClassOfStockTable_ef61056e-48b6-4b32-9f29-47c1aa1cca66" xlink:to="loc_us-gaap_StatementClassOfStockAxis_d3b17bd7-25f1-41f8-9d6f-b007bd7b8d30" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_d3b17bd7-25f1-41f8-9d6f-b007bd7b8d30_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_d3b17bd7-25f1-41f8-9d6f-b007bd7b8d30" xlink:to="loc_us-gaap_ClassOfStockDomain_d3b17bd7-25f1-41f8-9d6f-b007bd7b8d30_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_9766737f-9317-436c-832b-78f0ea1af87f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_d3b17bd7-25f1-41f8-9d6f-b007bd7b8d30" xlink:to="loc_us-gaap_ClassOfStockDomain_9766737f-9317-436c-832b-78f0ea1af87f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesDPreferredStockMember_9b09c4d7-3f35-40ca-a88e-d94d58624000" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeriesDPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_9766737f-9317-436c-832b-78f0ea1af87f" xlink:to="loc_us-gaap_SeriesDPreferredStockMember_9b09c4d7-3f35-40ca-a88e-d94d58624000" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesBPreferredStockMember_870a54b4-d392-4b78-924c-d94cc7a1b7af" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeriesBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_9766737f-9317-436c-832b-78f0ea1af87f" xlink:to="loc_us-gaap_SeriesBPreferredStockMember_870a54b4-d392-4b78-924c-d94cc7a1b7af" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/RevenuefromContractswithCustomersSummaryofRevenuefromContractswithCustomersDetail" xlink:type="simple" xlink:href="nnbr-20220930.xsd#RevenuefromContractswithCustomersSummaryofRevenuefromContractswithCustomersDetail"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/RevenuefromContractswithCustomersSummaryofRevenuefromContractswithCustomersDetail" xlink:type="extended" id="i70b24412fe9b41f98118ca2afb96d1a1_RevenuefromContractswithCustomersSummaryofRevenuefromContractswithCustomersDetail">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_fb4556e2-115a-41f7-8a8b-092c6f30a9d5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EntityWideRevenueMajorCustomerLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_1c438c05-d053-4952-81e8-98fd26286737" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_fb4556e2-115a-41f7-8a8b-092c6f30a9d5" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_1c438c05-d053-4952-81e8-98fd26286737" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_a8a9c5a5-e801-47a4-91e2-5575afb85033" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_fb4556e2-115a-41f7-8a8b-092c6f30a9d5" xlink:to="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_a8a9c5a5-e801-47a4-91e2-5575afb85033" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_ec7b4bfe-2625-435c-ae80-0d5e17f81e9f" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_a8a9c5a5-e801-47a4-91e2-5575afb85033" xlink:to="loc_srt_ConsolidationItemsAxis_ec7b4bfe-2625-435c-ae80-0d5e17f81e9f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_ec7b4bfe-2625-435c-ae80-0d5e17f81e9f_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_ec7b4bfe-2625-435c-ae80-0d5e17f81e9f" xlink:to="loc_srt_ConsolidationItemsDomain_ec7b4bfe-2625-435c-ae80-0d5e17f81e9f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_a5715aff-d998-4613-ad00-aaa1faf6e50e" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_ec7b4bfe-2625-435c-ae80-0d5e17f81e9f" xlink:to="loc_srt_ConsolidationItemsDomain_a5715aff-d998-4613-ad00-aaa1faf6e50e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_ad5d17c4-66ee-4cfd-8658-30504a69ca45" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_a5715aff-d998-4613-ad00-aaa1faf6e50e" xlink:to="loc_us-gaap_OperatingSegmentsMember_ad5d17c4-66ee-4cfd-8658-30504a69ca45" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_f14638f1-2bae-41a5-bca3-1330c4040cff" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IntersegmentEliminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_a5715aff-d998-4613-ad00-aaa1faf6e50e" xlink:to="loc_us-gaap_IntersegmentEliminationMember_f14638f1-2bae-41a5-bca3-1330c4040cff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_8ab810c4-f44d-4484-b6e1-70b814c773d9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_a8a9c5a5-e801-47a4-91e2-5575afb85033" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_8ab810c4-f44d-4484-b6e1-70b814c773d9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_8ab810c4-f44d-4484-b6e1-70b814c773d9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_8ab810c4-f44d-4484-b6e1-70b814c773d9" xlink:to="loc_us-gaap_SegmentDomain_8ab810c4-f44d-4484-b6e1-70b814c773d9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_d57e1f61-3474-4c9c-8101-deeebb8a2fca" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_8ab810c4-f44d-4484-b6e1-70b814c773d9" xlink:to="loc_us-gaap_SegmentDomain_d57e1f61-3474-4c9c-8101-deeebb8a2fca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_MobileSolutionsMember_d749af17-2257-48d0-92c0-bbdeb6fd505b" xlink:href="nnbr-20220930.xsd#nnbr_MobileSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_d57e1f61-3474-4c9c-8101-deeebb8a2fca" xlink:to="loc_nnbr_MobileSolutionsMember_d749af17-2257-48d0-92c0-bbdeb6fd505b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_PowerSolutionsMember_9f252bd4-5e51-4c01-b4a0-7c9a86f5a986" xlink:href="nnbr-20220930.xsd#nnbr_PowerSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_d57e1f61-3474-4c9c-8101-deeebb8a2fca" xlink:to="loc_nnbr_PowerSolutionsMember_9f252bd4-5e51-4c01-b4a0-7c9a86f5a986" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_24b2dbe2-b96c-420b-b66e-f942628ea3e7" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_a8a9c5a5-e801-47a4-91e2-5575afb85033" xlink:to="loc_srt_StatementGeographicalAxis_24b2dbe2-b96c-420b-b66e-f942628ea3e7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_24b2dbe2-b96c-420b-b66e-f942628ea3e7_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_24b2dbe2-b96c-420b-b66e-f942628ea3e7" xlink:to="loc_srt_SegmentGeographicalDomain_24b2dbe2-b96c-420b-b66e-f942628ea3e7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_cb6ba7c2-eb4b-4ecf-8ea1-8f6e51e97b63" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_24b2dbe2-b96c-420b-b66e-f942628ea3e7" xlink:to="loc_srt_SegmentGeographicalDomain_cb6ba7c2-eb4b-4ecf-8ea1-8f6e51e97b63" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_1124d957-0b78-4aa5-bd76-8d9f5b172ae9" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_cb6ba7c2-eb4b-4ecf-8ea1-8f6e51e97b63" xlink:to="loc_country_US_1124d957-0b78-4aa5-bd76-8d9f5b172ae9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CN_d2b2f075-7572-4c7f-9ad2-ca4d537b0032" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_CN"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_cb6ba7c2-eb4b-4ecf-8ea1-8f6e51e97b63" xlink:to="loc_country_CN_d2b2f075-7572-4c7f-9ad2-ca4d537b0032" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_BR_ed14c545-d9b9-4652-9dbe-ea4ec64601a8" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_BR"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_cb6ba7c2-eb4b-4ecf-8ea1-8f6e51e97b63" xlink:to="loc_country_BR_ed14c545-d9b9-4652-9dbe-ea4ec64601a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_MX_484fd1b2-d4d5-4408-9f71-5b4643d86e60" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_MX"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_cb6ba7c2-eb4b-4ecf-8ea1-8f6e51e97b63" xlink:to="loc_country_MX_484fd1b2-d4d5-4408-9f71-5b4643d86e60" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_DE_33f84758-5a8d-44ee-8c42-476b4933b474" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_DE"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_cb6ba7c2-eb4b-4ecf-8ea1-8f6e51e97b63" xlink:to="loc_country_DE_33f84758-5a8d-44ee-8c42-476b4933b474" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_PL_309dbc08-5176-46bb-bee4-63339fb26e23" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_PL"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_cb6ba7c2-eb4b-4ecf-8ea1-8f6e51e97b63" xlink:to="loc_country_PL_309dbc08-5176-46bb-bee4-63339fb26e23" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_OtherCountryMember_b03369db-9129-4df7-b464-d2c9721ee59a" xlink:href="nnbr-20220930.xsd#nnbr_OtherCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_cb6ba7c2-eb4b-4ecf-8ea1-8f6e51e97b63" xlink:to="loc_nnbr_OtherCountryMember_b03369db-9129-4df7-b464-d2c9721ee59a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_d5659a87-bea6-4c8c-9934-8bcbe73306ba" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_a8a9c5a5-e801-47a4-91e2-5575afb85033" xlink:to="loc_srt_ProductOrServiceAxis_d5659a87-bea6-4c8c-9934-8bcbe73306ba" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_d5659a87-bea6-4c8c-9934-8bcbe73306ba_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_d5659a87-bea6-4c8c-9934-8bcbe73306ba" xlink:to="loc_srt_ProductsAndServicesDomain_d5659a87-bea6-4c8c-9934-8bcbe73306ba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_00cafac6-0197-4fee-ada9-22280a505c19" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_d5659a87-bea6-4c8c-9934-8bcbe73306ba" xlink:to="loc_srt_ProductsAndServicesDomain_00cafac6-0197-4fee-ada9-22280a505c19" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_AutomotiveMember_03988a6c-5a27-4cae-94bf-23edaf6b43f0" xlink:href="nnbr-20220930.xsd#nnbr_AutomotiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_00cafac6-0197-4fee-ada9-22280a505c19" xlink:to="loc_nnbr_AutomotiveMember_03988a6c-5a27-4cae-94bf-23edaf6b43f0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_GeneralIndustrialMember_65a3aa4c-a372-4ef3-9b92-ac636fbaebfa" xlink:href="nnbr-20220930.xsd#nnbr_GeneralIndustrialMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_00cafac6-0197-4fee-ada9-22280a505c19" xlink:to="loc_nnbr_GeneralIndustrialMember_65a3aa4c-a372-4ef3-9b92-ac636fbaebfa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_ElectricalMember_3bab9798-8a06-449d-b319-ffc268994b7c" xlink:href="nnbr-20220930.xsd#nnbr_ElectricalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_00cafac6-0197-4fee-ada9-22280a505c19" xlink:to="loc_nnbr_ElectricalMember_3bab9798-8a06-449d-b319-ffc268994b7c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_OtherEndMarketMember_a45768d8-a0bc-4b6a-9985-31a83f913c26" xlink:href="nnbr-20220930.xsd#nnbr_OtherEndMarketMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_00cafac6-0197-4fee-ada9-22280a505c19" xlink:to="loc_nnbr_OtherEndMarketMember_a45768d8-a0bc-4b6a-9985-31a83f913c26" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/RevenuefromContractswithCustomersAdditionalInformationDetails" xlink:type="simple" xlink:href="nnbr-20220930.xsd#RevenuefromContractswithCustomersAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/RevenuefromContractswithCustomersAdditionalInformationDetails" xlink:type="extended" id="i7a1e0545cdec4571bdc479fca1cbd039_RevenuefromContractswithCustomersAdditionalInformationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7b0de0ea-fbea-4716-b8c9-194fed77e7e2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EntityWideRevenueMajorCustomerLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_6db5dc5c-4983-40fe-b363-7a03e35b8be5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7b0de0ea-fbea-4716-b8c9-194fed77e7e2" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_6db5dc5c-4983-40fe-b363-7a03e35b8be5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_52aab757-018c-4fc3-b511-26f8eb83f6d7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7b0de0ea-fbea-4716-b8c9-194fed77e7e2" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_52aab757-018c-4fc3-b511-26f8eb83f6d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_f75cebf2-b8e3-4908-a7e7-483e7fa9cd77" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7b0de0ea-fbea-4716-b8c9-194fed77e7e2" xlink:to="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_f75cebf2-b8e3-4908-a7e7-483e7fa9cd77" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_6f244928-86fe-405c-bbc3-86779f3dbbbf" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_f75cebf2-b8e3-4908-a7e7-483e7fa9cd77" xlink:to="loc_srt_MajorCustomersAxis_6f244928-86fe-405c-bbc3-86779f3dbbbf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_6f244928-86fe-405c-bbc3-86779f3dbbbf_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_6f244928-86fe-405c-bbc3-86779f3dbbbf" xlink:to="loc_srt_NameOfMajorCustomerDomain_6f244928-86fe-405c-bbc3-86779f3dbbbf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_c68a8f9f-6ea1-42f9-9b81-dd58e81215d9" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_6f244928-86fe-405c-bbc3-86779f3dbbbf" xlink:to="loc_srt_NameOfMajorCustomerDomain_c68a8f9f-6ea1-42f9-9b81-dd58e81215d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_MajorCustomerMember_197db4de-db00-4537-9c81-25d7967b077e" xlink:href="nnbr-20220930.xsd#nnbr_MajorCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_c68a8f9f-6ea1-42f9-9b81-dd58e81215d9" xlink:to="loc_nnbr_MajorCustomerMember_197db4de-db00-4537-9c81-25d7967b077e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_4d3b1392-5160-46a2-a61d-eae9b449bab2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_f75cebf2-b8e3-4908-a7e7-483e7fa9cd77" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_4d3b1392-5160-46a2-a61d-eae9b449bab2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_4d3b1392-5160-46a2-a61d-eae9b449bab2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_4d3b1392-5160-46a2-a61d-eae9b449bab2" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_4d3b1392-5160-46a2-a61d-eae9b449bab2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_c1a49b09-c8c4-48ec-8be6-78d8c5f5801f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_4d3b1392-5160-46a2-a61d-eae9b449bab2" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_c1a49b09-c8c4-48ec-8be6-78d8c5f5801f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_001a89a0-8692-4baa-971d-35fc37a1f822" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_c1a49b09-c8c4-48ec-8be6-78d8c5f5801f" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_001a89a0-8692-4baa-971d-35fc37a1f822" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_b5ce01f5-bbdd-43c4-9382-38a31ded34d2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_f75cebf2-b8e3-4908-a7e7-483e7fa9cd77" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_b5ce01f5-bbdd-43c4-9382-38a31ded34d2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_b5ce01f5-bbdd-43c4-9382-38a31ded34d2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_b5ce01f5-bbdd-43c4-9382-38a31ded34d2" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_b5ce01f5-bbdd-43c4-9382-38a31ded34d2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_a781eda6-baf9-4c94-93a8-3796b9fd0e83" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_b5ce01f5-bbdd-43c4-9382-38a31ded34d2" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_a781eda6-baf9-4c94-93a8-3796b9fd0e83" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_78eaca73-055b-4eae-9ddd-426c2a6220d0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_a781eda6-baf9-4c94-93a8-3796b9fd0e83" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_78eaca73-055b-4eae-9ddd-426c2a6220d0" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/SharedBasedCompensationAdditionalInformationDetail" xlink:type="simple" xlink:href="nnbr-20220930.xsd#SharedBasedCompensationAdditionalInformationDetail"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/SharedBasedCompensationAdditionalInformationDetail" xlink:type="extended" id="i4042ec8f81fb467787f7a57d4a098b91_SharedBasedCompensationAdditionalInformationDetail">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_d43d84c3-e27c-4f41-b3d8-f1bc47c2245d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_0ecf936b-f648-410a-ac85-e33984ec13f9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_d43d84c3-e27c-4f41-b3d8-f1bc47c2245d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_0ecf936b-f648-410a-ac85-e33984ec13f9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_9084ea4d-bb1a-4766-88f3-b4ba9145a55d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_d43d84c3-e27c-4f41-b3d8-f1bc47c2245d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_9084ea4d-bb1a-4766-88f3-b4ba9145a55d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice_b68c88b9-18ba-4c5c-ac43-6b4c470cb9aa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_d43d84c3-e27c-4f41-b3d8-f1bc47c2245d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice_b68c88b9-18ba-4c5c-ac43-6b4c470cb9aa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_b1632523-ee1c-43c3-b2b6-faa568cd6584" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_d43d84c3-e27c-4f41-b3d8-f1bc47c2245d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_b1632523-ee1c-43c3-b2b6-faa568cd6584" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPerformancePeriod_0331efca-d4aa-4304-926e-07ac9fdb34f5" xlink:href="nnbr-20220930.xsd#nnbr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPerformancePeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_d43d84c3-e27c-4f41-b3d8-f1bc47c2245d" xlink:to="loc_nnbr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPerformancePeriod_0331efca-d4aa-4304-926e-07ac9fdb34f5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfSharesIssuableBasedOnThresholdPerformance_c8aba745-ac00-4b86-b3ec-dd757a4d95e2" xlink:href="nnbr-20220930.xsd#nnbr_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfSharesIssuableBasedOnThresholdPerformance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_d43d84c3-e27c-4f41-b3d8-f1bc47c2245d" xlink:to="loc_nnbr_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfSharesIssuableBasedOnThresholdPerformance_c8aba745-ac00-4b86-b3ec-dd757a4d95e2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_ShareBasedCompensationArrangementBySharebasedPaymentAwardPercentageOfSharesIssuableBasedOnTargetPerformance_49c0e82b-4fbe-47fa-a9a1-29096b108294" xlink:href="nnbr-20220930.xsd#nnbr_ShareBasedCompensationArrangementBySharebasedPaymentAwardPercentageOfSharesIssuableBasedOnTargetPerformance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_d43d84c3-e27c-4f41-b3d8-f1bc47c2245d" xlink:to="loc_nnbr_ShareBasedCompensationArrangementBySharebasedPaymentAwardPercentageOfSharesIssuableBasedOnTargetPerformance_49c0e82b-4fbe-47fa-a9a1-29096b108294" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_ShareBasedCompensationArrangementBySharebasedPaymentAwardPercentageOfSharesIssuableBasedOnMaximumPerformance_6d6271f1-bc17-442a-99f3-bec2378ac276" xlink:href="nnbr-20220930.xsd#nnbr_ShareBasedCompensationArrangementBySharebasedPaymentAwardPercentageOfSharesIssuableBasedOnMaximumPerformance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_d43d84c3-e27c-4f41-b3d8-f1bc47c2245d" xlink:to="loc_nnbr_ShareBasedCompensationArrangementBySharebasedPaymentAwardPercentageOfSharesIssuableBasedOnMaximumPerformance_6d6271f1-bc17-442a-99f3-bec2378ac276" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_33623805-9c36-495a-8cb9-54d3e86f279f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_d43d84c3-e27c-4f41-b3d8-f1bc47c2245d" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_33623805-9c36-495a-8cb9-54d3e86f279f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_2aea4be4-b111-4a40-9108-c1389c1c56cc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_d43d84c3-e27c-4f41-b3d8-f1bc47c2245d" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_2aea4be4-b111-4a40-9108-c1389c1c56cc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualAxis_51904c6d-e23d-4fde-8804-243f7a304b53" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_TitleOfIndividualAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_2aea4be4-b111-4a40-9108-c1389c1c56cc" xlink:to="loc_srt_TitleOfIndividualAxis_51904c6d-e23d-4fde-8804-243f7a304b53" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_51904c6d-e23d-4fde-8804-243f7a304b53_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_TitleOfIndividualAxis_51904c6d-e23d-4fde-8804-243f7a304b53" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_51904c6d-e23d-4fde-8804-243f7a304b53_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_4865ffd7-4c79-4e57-8667-b425ba66af9c" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_TitleOfIndividualAxis_51904c6d-e23d-4fde-8804-243f7a304b53" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_4865ffd7-4c79-4e57-8667-b425ba66af9c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_EmployeesMember_4f656dcf-c280-43d0-8c05-607e4bdd8e4b" xlink:href="nnbr-20220930.xsd#nnbr_EmployeesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_4865ffd7-4c79-4e57-8667-b425ba66af9c" xlink:to="loc_nnbr_EmployeesMember_4f656dcf-c280-43d0-8c05-607e4bdd8e4b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_NonExecutiveDirectorsMember_528003b1-40e7-4232-8950-accad0d38fa2" xlink:href="nnbr-20220930.xsd#nnbr_NonExecutiveDirectorsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_4865ffd7-4c79-4e57-8667-b425ba66af9c" xlink:to="loc_nnbr_NonExecutiveDirectorsMember_528003b1-40e7-4232-8950-accad0d38fa2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_18a48dec-c00d-4b49-a162-2e201f103399" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_2aea4be4-b111-4a40-9108-c1389c1c56cc" xlink:to="loc_us-gaap_AwardTypeAxis_18a48dec-c00d-4b49-a162-2e201f103399" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_18a48dec-c00d-4b49-a162-2e201f103399_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_18a48dec-c00d-4b49-a162-2e201f103399" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_18a48dec-c00d-4b49-a162-2e201f103399_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_39f0492f-cb39-4b06-905d-d027360f6ee9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_18a48dec-c00d-4b49-a162-2e201f103399" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_39f0492f-cb39-4b06-905d-d027360f6ee9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_6c114f74-8be9-4d20-95be-3f94c1038e9a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_39f0492f-cb39-4b06-905d-d027360f6ee9" xlink:to="loc_us-gaap_RestrictedStockMember_6c114f74-8be9-4d20-95be-3f94c1038e9a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_PerformanceSharesTsrAwardsMember_04437433-f45e-42d1-b065-b9e1e974a547" xlink:href="nnbr-20220930.xsd#nnbr_PerformanceSharesTsrAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_39f0492f-cb39-4b06-905d-d027360f6ee9" xlink:to="loc_nnbr_PerformanceSharesTsrAwardsMember_04437433-f45e-42d1-b065-b9e1e974a547" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_PerformanceSharesReturnOnInvestedCapitalMember_5f7e4134-6dfa-4261-bc92-75fd1bb1ac3c" xlink:href="nnbr-20220930.xsd#nnbr_PerformanceSharesReturnOnInvestedCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_39f0492f-cb39-4b06-905d-d027360f6ee9" xlink:to="loc_nnbr_PerformanceSharesReturnOnInvestedCapitalMember_5f7e4134-6dfa-4261-bc92-75fd1bb1ac3c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInAccountingMethodAccountedForAsChangeInEstimateMember_f41df721-7839-440f-a318-2150cdd115b7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ChangeInAccountingMethodAccountedForAsChangeInEstimateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_39f0492f-cb39-4b06-905d-d027360f6ee9" xlink:to="loc_us-gaap_ChangeInAccountingMethodAccountedForAsChangeInEstimateMember_f41df721-7839-440f-a318-2150cdd115b7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_e9190567-58b0-4a88-9a42-c4b66f0de8e6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOperatingActivitiesSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_2aea4be4-b111-4a40-9108-c1389c1c56cc" xlink:to="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_e9190567-58b0-4a88-9a42-c4b66f0de8e6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentOperatingActivitiesDomain_e9190567-58b0-4a88-9a42-c4b66f0de8e6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentOperatingActivitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_e9190567-58b0-4a88-9a42-c4b66f0de8e6" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_e9190567-58b0-4a88-9a42-c4b66f0de8e6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentOperatingActivitiesDomain_17ae2063-107e-46cd-a486-929c469fcb84" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentOperatingActivitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_e9190567-58b0-4a88-9a42-c4b66f0de8e6" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_17ae2063-107e-46cd-a486-929c469fcb84" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDiscontinuedOperationsMember_6b9d7263-8604-4e31-be11-1da0d0cee6c8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDiscontinuedOperationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentOperatingActivitiesDomain_17ae2063-107e-46cd-a486-929c469fcb84" xlink:to="loc_us-gaap_SegmentDiscontinuedOperationsMember_6b9d7263-8604-4e31-be11-1da0d0cee6c8" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/SharedBasedCompensationComponentsofShareBasedCompensationExpensebyTypeofAwardDetail" xlink:type="simple" xlink:href="nnbr-20220930.xsd#SharedBasedCompensationComponentsofShareBasedCompensationExpensebyTypeofAwardDetail"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/SharedBasedCompensationComponentsofShareBasedCompensationExpensebyTypeofAwardDetail" xlink:type="extended" id="id8f9951a7e50445baf3bb4d74757728d_SharedBasedCompensationComponentsofShareBasedCompensationExpensebyTypeofAwardDetail">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_c9f57ad8-0429-4224-8f9a-8935823e6127" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_b49dfe9a-3434-49ed-902c-c184052158d7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_c9f57ad8-0429-4224-8f9a-8935823e6127" xlink:to="loc_us-gaap_ShareBasedCompensation_b49dfe9a-3434-49ed-902c-c184052158d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_da300448-24e0-4ab8-9803-c2359ade07c0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_c9f57ad8-0429-4224-8f9a-8935823e6127" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_da300448-24e0-4ab8-9803-c2359ade07c0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_b86211f2-9ecc-445f-b821-da00373d85bb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_da300448-24e0-4ab8-9803-c2359ade07c0" xlink:to="loc_us-gaap_AwardTypeAxis_b86211f2-9ecc-445f-b821-da00373d85bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b86211f2-9ecc-445f-b821-da00373d85bb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_b86211f2-9ecc-445f-b821-da00373d85bb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b86211f2-9ecc-445f-b821-da00373d85bb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d1fee537-8efa-4ab3-a238-cf831d2863c6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_b86211f2-9ecc-445f-b821-da00373d85bb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d1fee537-8efa-4ab3-a238-cf831d2863c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_aeb9996b-4d01-4e87-bf3a-fb1731b95ddb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d1fee537-8efa-4ab3-a238-cf831d2863c6" xlink:to="loc_us-gaap_EmployeeStockOptionMember_aeb9996b-4d01-4e87-bf3a-fb1731b95ddb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_04563a47-3119-475f-a8a1-0449c56e77f0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d1fee537-8efa-4ab3-a238-cf831d2863c6" xlink:to="loc_us-gaap_RestrictedStockMember_04563a47-3119-475f-a8a1-0449c56e77f0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_4be6ca65-3cbe-4d12-8ef0-c1936d7e9ff2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d1fee537-8efa-4ab3-a238-cf831d2863c6" xlink:to="loc_us-gaap_PerformanceSharesMember_4be6ca65-3cbe-4d12-8ef0-c1936d7e9ff2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInAccountingMethodAccountedForAsChangeInEstimateMember_b8e5cb56-d75b-4116-b800-7e28eedd1ade" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ChangeInAccountingMethodAccountedForAsChangeInEstimateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d1fee537-8efa-4ab3-a238-cf831d2863c6" xlink:to="loc_us-gaap_ChangeInAccountingMethodAccountedForAsChangeInEstimateMember_b8e5cb56-d75b-4116-b800-7e28eedd1ade" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_ChangeinEstimateofPerformanceSharesMember_8c7463c3-8d31-4ee5-881c-94792803ac81" xlink:href="nnbr-20220930.xsd#nnbr_ChangeinEstimateofPerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d1fee537-8efa-4ab3-a238-cf831d2863c6" xlink:to="loc_nnbr_ChangeinEstimateofPerformanceSharesMember_8c7463c3-8d31-4ee5-881c-94792803ac81" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_c2d6a3df-8bf3-42a8-a072-6e6107bee8bc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOperatingActivitiesSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_da300448-24e0-4ab8-9803-c2359ade07c0" xlink:to="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_c2d6a3df-8bf3-42a8-a072-6e6107bee8bc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentOperatingActivitiesDomain_c2d6a3df-8bf3-42a8-a072-6e6107bee8bc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentOperatingActivitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_c2d6a3df-8bf3-42a8-a072-6e6107bee8bc" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_c2d6a3df-8bf3-42a8-a072-6e6107bee8bc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentOperatingActivitiesDomain_aff91f16-405d-4483-b99d-2ac9b82c1917" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentOperatingActivitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_c2d6a3df-8bf3-42a8-a072-6e6107bee8bc" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_aff91f16-405d-4483-b99d-2ac9b82c1917" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDiscontinuedOperationsMember_e8f761f7-95c4-41c0-97d7-0c290f752a08" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDiscontinuedOperationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentOperatingActivitiesDomain_aff91f16-405d-4483-b99d-2ac9b82c1917" xlink:to="loc_us-gaap_SegmentDiscontinuedOperationsMember_e8f761f7-95c4-41c0-97d7-0c290f752a08" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/SharedBasedCompensationReconciliationofRestrictedStockOptionActivityDetail" xlink:type="simple" xlink:href="nnbr-20220930.xsd#SharedBasedCompensationReconciliationofRestrictedStockOptionActivityDetail"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/SharedBasedCompensationReconciliationofRestrictedStockOptionActivityDetail" xlink:type="extended" id="iba8c1fd18c98469199c6089a38558dd3_SharedBasedCompensationReconciliationofRestrictedStockOptionActivityDetail">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_481c8a02-a222-4eec-8b2c-b4ed1c81bbfa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_5b58aafc-bf85-42a3-816a-77a6d90f32d8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_481c8a02-a222-4eec-8b2c-b4ed1c81bbfa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_5b58aafc-bf85-42a3-816a-77a6d90f32d8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_bcfe2ceb-6d2a-462c-ab79-ac5eba177f6b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_5b58aafc-bf85-42a3-816a-77a6d90f32d8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_bcfe2ceb-6d2a-462c-ab79-ac5eba177f6b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_430732e4-3093-491d-a1a3-85a68b3bf05d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_5b58aafc-bf85-42a3-816a-77a6d90f32d8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_430732e4-3093-491d-a1a3-85a68b3bf05d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_79e5dbee-9e15-47c7-9439-128b7689df3c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_5b58aafc-bf85-42a3-816a-77a6d90f32d8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_79e5dbee-9e15-47c7-9439-128b7689df3c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_c9d94d5f-fb62-41af-bec3-ac5ff72e98a1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_5b58aafc-bf85-42a3-816a-77a6d90f32d8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_c9d94d5f-fb62-41af-bec3-ac5ff72e98a1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_995cd498-07a9-4957-b313-9ffdeb4e3a56" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract_723dd27d-a017-4916-a614-11d9703d1828" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_481c8a02-a222-4eec-8b2c-b4ed1c81bbfa" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract_723dd27d-a017-4916-a614-11d9703d1828" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_47c051b1-9323-42e6-993a-3204cdb79b13" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract_723dd27d-a017-4916-a614-11d9703d1828" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_47c051b1-9323-42e6-993a-3204cdb79b13" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_7d364943-4bc6-4c49-8352-bed94512ae92" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract_723dd27d-a017-4916-a614-11d9703d1828" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_7d364943-4bc6-4c49-8352-bed94512ae92" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_6744d278-1e77-44dc-a63a-ee669e9a6028" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract_723dd27d-a017-4916-a614-11d9703d1828" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_6744d278-1e77-44dc-a63a-ee669e9a6028" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_d876c3c0-e34b-41c3-af66-8f44741e4c81" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract_723dd27d-a017-4916-a614-11d9703d1828" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_d876c3c0-e34b-41c3-af66-8f44741e4c81" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_24533bfa-f7fe-4606-bc33-eccbe4e4da09" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_3880058d-a66b-438b-a014-e01a7149f7d1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_481c8a02-a222-4eec-8b2c-b4ed1c81bbfa" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_3880058d-a66b-438b-a014-e01a7149f7d1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_1bd0fbfc-6152-42b7-91c7-81a9953845f2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_3880058d-a66b-438b-a014-e01a7149f7d1" xlink:to="loc_us-gaap_AwardTypeAxis_1bd0fbfc-6152-42b7-91c7-81a9953845f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1bd0fbfc-6152-42b7-91c7-81a9953845f2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_1bd0fbfc-6152-42b7-91c7-81a9953845f2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1bd0fbfc-6152-42b7-91c7-81a9953845f2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_df51b48d-8e66-4dcd-b458-89b19de36990" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_1bd0fbfc-6152-42b7-91c7-81a9953845f2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_df51b48d-8e66-4dcd-b458-89b19de36990" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_f0efa2ad-6e91-426d-ae50-fb164209ff10" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_df51b48d-8e66-4dcd-b458-89b19de36990" xlink:to="loc_us-gaap_RestrictedStockMember_f0efa2ad-6e91-426d-ae50-fb164209ff10" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_PerformanceSharesTsrAwardsMember_2bf0659c-7353-4eb3-a2ef-685276960936" xlink:href="nnbr-20220930.xsd#nnbr_PerformanceSharesTsrAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_df51b48d-8e66-4dcd-b458-89b19de36990" xlink:to="loc_nnbr_PerformanceSharesTsrAwardsMember_2bf0659c-7353-4eb3-a2ef-685276960936" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_PerformanceSharesReturnOnInvestedCapitalMember_83ded928-5b43-47e3-9ab0-31b89d6b306b" xlink:href="nnbr-20220930.xsd#nnbr_PerformanceSharesReturnOnInvestedCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_df51b48d-8e66-4dcd-b458-89b19de36990" xlink:to="loc_nnbr_PerformanceSharesReturnOnInvestedCapitalMember_83ded928-5b43-47e3-9ab0-31b89d6b306b" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/SharedBasedCompensationScheduleofPerformanceBasedAwardsGoalswithRespecttoTSRandROICDetail" xlink:type="simple" xlink:href="nnbr-20220930.xsd#SharedBasedCompensationScheduleofPerformanceBasedAwardsGoalswithRespecttoTSRandROICDetail"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/SharedBasedCompensationScheduleofPerformanceBasedAwardsGoalswithRespecttoTSRandROICDetail" xlink:type="extended" id="i5419f8317a3346b5a2e22d52051faec4_SharedBasedCompensationScheduleofPerformanceBasedAwardsGoalswithRespecttoTSRandROICDetail">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_5c6070af-c69e-41cb-9792-eb71bbc7fa17" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_ShareBasedCompensationArrangementByShareBasedPaymentAwardBasedOnThresholdPerformanceAchievementPercentage_14abcee3-ea34-48f7-be77-f561a1a70d6b" xlink:href="nnbr-20220930.xsd#nnbr_ShareBasedCompensationArrangementByShareBasedPaymentAwardBasedOnThresholdPerformanceAchievementPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_5c6070af-c69e-41cb-9792-eb71bbc7fa17" xlink:to="loc_nnbr_ShareBasedCompensationArrangementByShareBasedPaymentAwardBasedOnThresholdPerformanceAchievementPercentage_14abcee3-ea34-48f7-be77-f561a1a70d6b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_ShareBasedCompensationArrangementBySharebasedPaymentAwardBasedOnTargetPerformanceAchievementPercentage_b2375b55-5b57-453d-aa74-eb38251b18e6" xlink:href="nnbr-20220930.xsd#nnbr_ShareBasedCompensationArrangementBySharebasedPaymentAwardBasedOnTargetPerformanceAchievementPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_5c6070af-c69e-41cb-9792-eb71bbc7fa17" xlink:to="loc_nnbr_ShareBasedCompensationArrangementBySharebasedPaymentAwardBasedOnTargetPerformanceAchievementPercentage_b2375b55-5b57-453d-aa74-eb38251b18e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_ShareBasedCompensationArrangementBySharebasedPaymentAwardBasedOnMaximumPerformanceAchievementPercentage_b53116aa-3f96-43fe-890b-5d52cc98c6d2" xlink:href="nnbr-20220930.xsd#nnbr_ShareBasedCompensationArrangementBySharebasedPaymentAwardBasedOnMaximumPerformanceAchievementPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_5c6070af-c69e-41cb-9792-eb71bbc7fa17" xlink:to="loc_nnbr_ShareBasedCompensationArrangementBySharebasedPaymentAwardBasedOnMaximumPerformanceAchievementPercentage_b53116aa-3f96-43fe-890b-5d52cc98c6d2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_ddc7db73-c711-49d8-acb2-bab13d5dc009" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_5c6070af-c69e-41cb-9792-eb71bbc7fa17" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_ddc7db73-c711-49d8-acb2-bab13d5dc009" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_5e52d8b0-4eb4-4a8c-9b5f-daf19293f9b4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_ddc7db73-c711-49d8-acb2-bab13d5dc009" xlink:to="loc_us-gaap_AwardTypeAxis_5e52d8b0-4eb4-4a8c-9b5f-daf19293f9b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_5e52d8b0-4eb4-4a8c-9b5f-daf19293f9b4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_5e52d8b0-4eb4-4a8c-9b5f-daf19293f9b4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_5e52d8b0-4eb4-4a8c-9b5f-daf19293f9b4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d4588be2-e61d-439f-9a55-3bb3f615b540" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_5e52d8b0-4eb4-4a8c-9b5f-daf19293f9b4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d4588be2-e61d-439f-9a55-3bb3f615b540" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_PerformanceSharesTsrAwardsMember_da6c28ff-093e-420d-a559-a828a4710606" xlink:href="nnbr-20220930.xsd#nnbr_PerformanceSharesTsrAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d4588be2-e61d-439f-9a55-3bb3f615b540" xlink:to="loc_nnbr_PerformanceSharesTsrAwardsMember_da6c28ff-093e-420d-a559-a828a4710606" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_PerformanceSharesReturnOnInvestedCapitalMember_d7d24839-6601-4405-8678-8678f95055da" xlink:href="nnbr-20220930.xsd#nnbr_PerformanceSharesReturnOnInvestedCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d4588be2-e61d-439f-9a55-3bb3f615b540" xlink:to="loc_nnbr_PerformanceSharesReturnOnInvestedCapitalMember_d7d24839-6601-4405-8678-8678f95055da" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/SharedBasedCompensationSummaryofNumberofAwardsGrantedandGrandDateFairValueDetail" xlink:type="simple" xlink:href="nnbr-20220930.xsd#SharedBasedCompensationSummaryofNumberofAwardsGrantedandGrandDateFairValueDetail"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/SharedBasedCompensationSummaryofNumberofAwardsGrantedandGrandDateFairValueDetail" xlink:type="extended" id="ie741aaf44c614d5aaf046e988f18a6bc_SharedBasedCompensationSummaryofNumberofAwardsGrantedandGrandDateFairValueDetail">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_9e37302b-dd28-4cab-91da-fa1050a7d244" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_64419aa2-50b9-4d2b-b94c-17c518a6ffdb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_9e37302b-dd28-4cab-91da-fa1050a7d244" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_64419aa2-50b9-4d2b-b94c-17c518a6ffdb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_b5cb6f9f-c331-432c-a7b3-7d39671e7429" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_9e37302b-dd28-4cab-91da-fa1050a7d244" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_b5cb6f9f-c331-432c-a7b3-7d39671e7429" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a7494e5c-6f46-4f7d-8d85-3078af0dc5d2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_9e37302b-dd28-4cab-91da-fa1050a7d244" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a7494e5c-6f46-4f7d-8d85-3078af0dc5d2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_08045a2a-5657-4619-ad8f-a0e282c19ae0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a7494e5c-6f46-4f7d-8d85-3078af0dc5d2" xlink:to="loc_us-gaap_AwardTypeAxis_08045a2a-5657-4619-ad8f-a0e282c19ae0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_08045a2a-5657-4619-ad8f-a0e282c19ae0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_08045a2a-5657-4619-ad8f-a0e282c19ae0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_08045a2a-5657-4619-ad8f-a0e282c19ae0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6d62d433-90dc-4941-9ab5-09e59ef53069" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_08045a2a-5657-4619-ad8f-a0e282c19ae0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6d62d433-90dc-4941-9ab5-09e59ef53069" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_PerformanceSharesTsrAwardsMember_31083e93-74e9-461b-a558-54612ae8cb92" xlink:href="nnbr-20220930.xsd#nnbr_PerformanceSharesTsrAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6d62d433-90dc-4941-9ab5-09e59ef53069" xlink:to="loc_nnbr_PerformanceSharesTsrAwardsMember_31083e93-74e9-461b-a558-54612ae8cb92" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_PerformanceSharesReturnOnInvestedCapitalMember_550a6ea2-59bc-4772-9efd-f8bef74c3c94" xlink:href="nnbr-20220930.xsd#nnbr_PerformanceSharesReturnOnInvestedCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6d62d433-90dc-4941-9ab5-09e59ef53069" xlink:to="loc_nnbr_PerformanceSharesReturnOnInvestedCapitalMember_550a6ea2-59bc-4772-9efd-f8bef74c3c94" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/AccumulatedOtherComprehensiveIncomeDetails" xlink:type="simple" xlink:href="nnbr-20220930.xsd#AccumulatedOtherComprehensiveIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/AccumulatedOtherComprehensiveIncomeDetails" xlink:type="extended" id="i2a29690d25034dbe9b8b8fbad004fdbe_AccumulatedOtherComprehensiveIncomeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3cbab7b6-c331-44f9-8fa6-a039c9455b12" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_24b8a7b3-a883-40bd-a29b-03cdba9870fe" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3cbab7b6-c331-44f9-8fa6-a039c9455b12" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_24b8a7b3-a883-40bd-a29b-03cdba9870fe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_e5e8775c-bf04-4319-a19a-abeb901a1a68" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_24b8a7b3-a883-40bd-a29b-03cdba9870fe" xlink:to="loc_us-gaap_StockholdersEquity_e5e8775c-bf04-4319-a19a-abeb901a1a68" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent_9c30dfb9-ba2e-4779-bdca-b4000bfc07a1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_24b8a7b3-a883-40bd-a29b-03cdba9870fe" xlink:to="loc_us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent_9c30dfb9-ba2e-4779-bdca-b4000bfc07a1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax_d5b79a5d-83e3-4824-96e3-5aea5c50d547" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_24b8a7b3-a883-40bd-a29b-03cdba9870fe" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax_d5b79a5d-83e3-4824-96e3-5aea5c50d547" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_529b94c3-f3ab-4f9f-afca-af0bd2e33162" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_24b8a7b3-a883-40bd-a29b-03cdba9870fe" xlink:to="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_529b94c3-f3ab-4f9f-afca-af0bd2e33162" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent_79c1b641-54b0-478a-aa6b-3d2b498068de" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_24b8a7b3-a883-40bd-a29b-03cdba9870fe" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent_79c1b641-54b0-478a-aa6b-3d2b498068de" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodTax_b47b6b35-ffec-4e04-bc8b-2b244221e8cb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationFromAociCurrentPeriodTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_24b8a7b3-a883-40bd-a29b-03cdba9870fe" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodTax_b47b6b35-ffec-4e04-bc8b-2b244221e8cb" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_4658d4d1-3dea-42d9-b0f6-2dbf007a6d8a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_24b8a7b3-a883-40bd-a29b-03cdba9870fe" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_4658d4d1-3dea-42d9-b0f6-2dbf007a6d8a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_d15a34eb-f0c7-4355-8e51-25ab01487f9f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_24b8a7b3-a883-40bd-a29b-03cdba9870fe" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_d15a34eb-f0c7-4355-8e51-25ab01487f9f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax_a3ffe472-39ab-432b-8ed2-8700a39b1475" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_24b8a7b3-a883-40bd-a29b-03cdba9870fe" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax_a3ffe472-39ab-432b-8ed2-8700a39b1475" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent_2731a0c8-ec70-4700-bbb6-1ec27590576a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_24b8a7b3-a883-40bd-a29b-03cdba9870fe" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent_2731a0c8-ec70-4700-bbb6-1ec27590576a" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossTax_db5b9a6c-3b36-45c8-be73-cad09c5949b7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_24b8a7b3-a883-40bd-a29b-03cdba9870fe" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossTax_db5b9a6c-3b36-45c8-be73-cad09c5949b7" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_9cafc107-21ce-4e10-b567-2d4ffdb33c7c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_24b8a7b3-a883-40bd-a29b-03cdba9870fe" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_9cafc107-21ce-4e10-b567-2d4ffdb33c7c" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_1f828a4c-31a1-4d6f-902d-e99260e1ca32" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_b4df9055-6e98-4e7a-bb30-cab4cfa1ef99" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3cbab7b6-c331-44f9-8fa6-a039c9455b12" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_b4df9055-6e98-4e7a-bb30-cab4cfa1ef99" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_e88ebc1e-aa39-436d-8ba0-b4bf99f0b14a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_b4df9055-6e98-4e7a-bb30-cab4cfa1ef99" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_e88ebc1e-aa39-436d-8ba0-b4bf99f0b14a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_e88ebc1e-aa39-436d-8ba0-b4bf99f0b14a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_e88ebc1e-aa39-436d-8ba0-b4bf99f0b14a" xlink:to="loc_us-gaap_EquityComponentDomain_e88ebc1e-aa39-436d-8ba0-b4bf99f0b14a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_a1434b95-38ed-4ddc-968e-fc40b6937f99" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_e88ebc1e-aa39-436d-8ba0-b4bf99f0b14a" xlink:to="loc_us-gaap_EquityComponentDomain_a1434b95-38ed-4ddc-968e-fc40b6937f99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_86025914-4b17-4c06-9670-a477cff47f91" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a1434b95-38ed-4ddc-968e-fc40b6937f99" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_86025914-4b17-4c06-9670-a477cff47f91" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_6597df8c-212b-41c0-a094-9c20c7469867" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_86025914-4b17-4c06-9670-a477cff47f91" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_6597df8c-212b-41c0-a094-9c20c7469867" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_77e30122-de9b-4ee6-afbb-61ac22e39d90" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_86025914-4b17-4c06-9670-a477cff47f91" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_77e30122-de9b-4ee6-afbb-61ac22e39d90" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_AOCIAttributableToParentTaxPortionMember_88975522-7d37-4854-b862-dd50ff43d1cf" xlink:href="nnbr-20220930.xsd#nnbr_AOCIAttributableToParentTaxPortionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_86025914-4b17-4c06-9670-a477cff47f91" xlink:to="loc_nnbr_AOCIAttributableToParentTaxPortionMember_88975522-7d37-4854-b862-dd50ff43d1cf" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_6c1a0666-f7fc-40d7-8809-104bb8527d2a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_b4df9055-6e98-4e7a-bb30-cab4cfa1ef99" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_6c1a0666-f7fc-40d7-8809-104bb8527d2a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_6c1a0666-f7fc-40d7-8809-104bb8527d2a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_6c1a0666-f7fc-40d7-8809-104bb8527d2a" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_6c1a0666-f7fc-40d7-8809-104bb8527d2a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_df17cdfd-cc4f-4880-9cd0-48517c0e2b05" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_6c1a0666-f7fc-40d7-8809-104bb8527d2a" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_df17cdfd-cc4f-4880-9cd0-48517c0e2b05" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_LossOnInterestRateSwapMember_cb3d24b4-00fa-4112-b33b-38167a287555" xlink:href="nnbr-20220930.xsd#nnbr_LossOnInterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_df17cdfd-cc4f-4880-9cd0-48517c0e2b05" xlink:to="loc_nnbr_LossOnInterestRateSwapMember_cb3d24b4-00fa-4112-b33b-38167a287555" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseMember_a17db0e7-87f0-4dba-9531-b48eddd70a19" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_df17cdfd-cc4f-4880-9cd0-48517c0e2b05" xlink:to="loc_us-gaap_InterestExpenseMember_a17db0e7-87f0-4dba-9531-b48eddd70a19" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_d9ade5da-37b6-4ddd-acd0-d39b627d0d1a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_b4df9055-6e98-4e7a-bb30-cab4cfa1ef99" xlink:to="loc_us-gaap_FinancialInstrumentAxis_d9ade5da-37b6-4ddd-acd0-d39b627d0d1a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_d9ade5da-37b6-4ddd-acd0-d39b627d0d1a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_d9ade5da-37b6-4ddd-acd0-d39b627d0d1a" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_d9ade5da-37b6-4ddd-acd0-d39b627d0d1a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_ef50cbee-b267-4bfb-a6ed-de6d3aeb757a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_d9ade5da-37b6-4ddd-acd0-d39b627d0d1a" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_ef50cbee-b267-4bfb-a6ed-de6d3aeb757a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeMember_a903ca5d-e9be-4719-bee4-5b357e09d1c6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_ef50cbee-b267-4bfb-a6ed-de6d3aeb757a" xlink:to="loc_us-gaap_DerivativeMember_a903ca5d-e9be-4719-bee4-5b357e09d1c6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_e6b61095-dba8-4b0a-bff1-aaf9f8fa5f84" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_b4df9055-6e98-4e7a-bb30-cab4cfa1ef99" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_e6b61095-dba8-4b0a-bff1-aaf9f8fa5f84" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_e6b61095-dba8-4b0a-bff1-aaf9f8fa5f84_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_e6b61095-dba8-4b0a-bff1-aaf9f8fa5f84" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_e6b61095-dba8-4b0a-bff1-aaf9f8fa5f84_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_adb2548f-0dc2-448a-ad99-844c89a08f8f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_e6b61095-dba8-4b0a-bff1-aaf9f8fa5f84" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_adb2548f-0dc2-448a-ad99-844c89a08f8f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_0330ec94-1337-4918-b58c-454075bdeaf8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_adb2548f-0dc2-448a-ad99-844c89a08f8f" xlink:to="loc_us-gaap_InterestRateSwapMember_0330ec94-1337-4918-b58c-454075bdeaf8" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/NetIncomeLossPerCommonShareAntidilutiveSecuritiesExcludedfromComputationDetails" xlink:type="simple" xlink:href="nnbr-20220930.xsd#NetIncomeLossPerCommonShareAntidilutiveSecuritiesExcludedfromComputationDetails"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/NetIncomeLossPerCommonShareAntidilutiveSecuritiesExcludedfromComputationDetails" xlink:type="extended" id="i99beec72ae0a4aea9302ae58988191d7_NetIncomeLossPerCommonShareAntidilutiveSecuritiesExcludedfromComputationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_4e8cd823-28bd-4e29-970b-a6012310f1f5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_7d4581c1-8f7a-4876-a293-56a1fa30e38e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_4e8cd823-28bd-4e29-970b-a6012310f1f5" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_7d4581c1-8f7a-4876-a293-56a1fa30e38e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_a839a528-9d35-4842-a95d-467e0fbaf0fa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_4e8cd823-28bd-4e29-970b-a6012310f1f5" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_a839a528-9d35-4842-a95d-467e0fbaf0fa" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_71432953-804b-4dcc-9015-322dcb6f9256" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_a839a528-9d35-4842-a95d-467e0fbaf0fa" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_71432953-804b-4dcc-9015-322dcb6f9256" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_71432953-804b-4dcc-9015-322dcb6f9256_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_71432953-804b-4dcc-9015-322dcb6f9256" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_71432953-804b-4dcc-9015-322dcb6f9256_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_373a50fe-e516-4b99-85b1-1418fc13887d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_71432953-804b-4dcc-9015-322dcb6f9256" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_373a50fe-e516-4b99-85b1-1418fc13887d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_6e48fbb1-eba1-4efd-b340-8363904ffad3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_373a50fe-e516-4b99-85b1-1418fc13887d" xlink:to="loc_us-gaap_EmployeeStockOptionMember_6e48fbb1-eba1-4efd-b340-8363904ffad3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_48d6f4df-c60d-4f7d-b5d2-1ad3bbabc8a7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_373a50fe-e516-4b99-85b1-1418fc13887d" xlink:to="loc_us-gaap_WarrantMember_48d6f4df-c60d-4f7d-b5d2-1ad3bbabc8a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember_fe9b8bb7-4ab2-44f0-a8d4-5a8661dba299" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_373a50fe-e516-4b99-85b1-1418fc13887d" xlink:to="loc_us-gaap_PreferredStockMember_fe9b8bb7-4ab2-44f0-a8d4-5a8661dba299" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/FairValueMeasurementsAdditionalInformationDetail" xlink:type="simple" xlink:href="nnbr-20220930.xsd#FairValueMeasurementsAdditionalInformationDetail"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/FairValueMeasurementsAdditionalInformationDetail" xlink:type="extended" id="iae97ad705ec14bd79f7752fe93a2711f_FairValueMeasurementsAdditionalInformationDetail">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_TemporaryEquityDividendsWithholdingsNetCashDistribution_a7548923-111a-4e85-9607-214cb1358cad" xlink:href="nnbr-20220930.xsd#nnbr_TemporaryEquityDividendsWithholdingsNetCashDistribution"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_nnbr_TemporaryEquityDividendsWithholdingsNetCashDistribution_a7548923-111a-4e85-9607-214cb1358cad" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_TemporaryEquityDividendsWithholdingsOffsetFromPurchasersUponRedemption_481d1fc4-0cbe-409e-94d9-ca5489c83cfc" xlink:href="nnbr-20220930.xsd#nnbr_TemporaryEquityDividendsWithholdingsOffsetFromPurchasersUponRedemption"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_nnbr_TemporaryEquityDividendsWithholdingsOffsetFromPurchasersUponRedemption_481d1fc4-0cbe-409e-94d9-ca5489c83cfc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_4eb1cc61-defa-4cb0-a9f9-ff45fc3c0bad" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_4eb1cc61-defa-4cb0-a9f9-ff45fc3c0bad" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_ClassOfWarrantOrRightAdjustedExercisePriceOfWarrantsOrRights_2b36717f-107e-47bc-8008-c9619136b99e" xlink:href="nnbr-20220930.xsd#nnbr_ClassOfWarrantOrRightAdjustedExercisePriceOfWarrantsOrRights"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_nnbr_ClassOfWarrantOrRightAdjustedExercisePriceOfWarrantsOrRights_2b36717f-107e-47bc-8008-c9619136b99e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_TemporaryEquityLiquidationPreferencePercentage_2a1048ee-26b4-4bd1-b930-69334e46435d" xlink:href="nnbr-20220930.xsd#nnbr_TemporaryEquityLiquidationPreferencePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_nnbr_TemporaryEquityLiquidationPreferencePercentage_2a1048ee-26b4-4bd1-b930-69334e46435d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_PreferredStockChangeInControlPutFeatureProbabilityPercentage_053d66f8-94bd-4a19-96bf-b8950e094c23" xlink:href="nnbr-20220930.xsd#nnbr_PreferredStockChangeInControlPutFeatureProbabilityPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_nnbr_PreferredStockChangeInControlPutFeatureProbabilityPercentage_053d66f8-94bd-4a19-96bf-b8950e094c23" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_PreferredStockRemainingInFuturePeriodsProbabilityPercentage_2a990aee-6cca-4edb-b835-aef52b881ef6" xlink:href="nnbr-20220930.xsd#nnbr_PreferredStockRemainingInFuturePeriodsProbabilityPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_nnbr_PreferredStockRemainingInFuturePeriodsProbabilityPercentage_2a990aee-6cca-4edb-b835-aef52b881ef6" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_PreferredStockPutFeatureExercisableProbabilityPercentage_e8a4fe5e-7188-4a9c-a3e1-f006757e21a4" xlink:href="nnbr-20220930.xsd#nnbr_PreferredStockPutFeatureExercisableProbabilityPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_nnbr_PreferredStockPutFeatureExercisableProbabilityPercentage_e8a4fe5e-7188-4a9c-a3e1-f006757e21a4" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstandingTerm_87fd95c3-7107-48d6-a458-b0f54d7cc5fe" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WarrantsAndRightsOutstandingTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_us-gaap_WarrantsAndRightsOutstandingTerm_87fd95c3-7107-48d6-a458-b0f54d7cc5fe" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFixedInterestRate_ca957d18-f9ea-43a9-adb7-766a07573b85" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeFixedInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_us-gaap_DerivativeFixedInterestRate_ca957d18-f9ea-43a9-adb7-766a07573b85" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForHedgeInvestingActivities_29b05828-d496-4be0-ba94-355b195bce80" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsForHedgeInvestingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_us-gaap_PaymentsForHedgeInvestingActivities_29b05828-d496-4be0-ba94-355b195bce80" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_743ad60a-75f4-4097-a7ea-6a2d880b41c7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_us-gaap_LineOfCredit_743ad60a-75f4-4097-a7ea-6a2d880b41c7" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_57047d99-9e46-4e92-ac64-76f58a3d773b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_us-gaap_LongTermDebtFairValue_57047d99-9e46-4e92-ac64-76f58a3d773b" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_66651a66-d6b2-4c39-a17e-f35f4ae171a6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_us-gaap_DerivativeNotionalAmount_66651a66-d6b2-4c39-a17e-f35f4ae171a6" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_bffd25e8-eec8-4fa3-8b1f-46873aece635" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_bffd25e8-eec8-4fa3-8b1f-46873aece635" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ab7705c2-650a-42d1-ace3-713320e628f8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b76b1692-45a6-44e3-a966-3c87c7a08ebd" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ab7705c2-650a-42d1-ace3-713320e628f8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_6540cdd6-91af-4f6c-a250-e0f01466acdd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ab7705c2-650a-42d1-ace3-713320e628f8" xlink:to="loc_us-gaap_StatementClassOfStockAxis_6540cdd6-91af-4f6c-a250-e0f01466acdd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_6540cdd6-91af-4f6c-a250-e0f01466acdd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_6540cdd6-91af-4f6c-a250-e0f01466acdd" xlink:to="loc_us-gaap_ClassOfStockDomain_6540cdd6-91af-4f6c-a250-e0f01466acdd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_8b7495b9-48b0-4cf1-9093-487b00e1323c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_6540cdd6-91af-4f6c-a250-e0f01466acdd" xlink:to="loc_us-gaap_ClassOfStockDomain_8b7495b9-48b0-4cf1-9093-487b00e1323c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesBPreferredStockMember_2746ac3e-5fcd-4380-bb4b-005a4ae0be9e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeriesBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_8b7495b9-48b0-4cf1-9093-487b00e1323c" xlink:to="loc_us-gaap_SeriesBPreferredStockMember_2746ac3e-5fcd-4380-bb4b-005a4ae0be9e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesDPreferredStockMember_8ca4e329-a342-4775-a377-021909f01f18" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeriesDPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_8b7495b9-48b0-4cf1-9093-487b00e1323c" xlink:to="loc_us-gaap_SeriesDPreferredStockMember_8ca4e329-a342-4775-a377-021909f01f18" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_SeriesBConvertiblePreferredStockMember_a4a53076-dbe1-4e15-acca-193f39261c44" xlink:href="nnbr-20220930.xsd#nnbr_SeriesBConvertiblePreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_8b7495b9-48b0-4cf1-9093-487b00e1323c" xlink:to="loc_nnbr_SeriesBConvertiblePreferredStockMember_a4a53076-dbe1-4e15-acca-193f39261c44" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_aa5f6973-84c5-490a-9e0e-4edced954498" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ab7705c2-650a-42d1-ace3-713320e628f8" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_aa5f6973-84c5-490a-9e0e-4edced954498" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_aa5f6973-84c5-490a-9e0e-4edced954498_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_aa5f6973-84c5-490a-9e0e-4edced954498" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_aa5f6973-84c5-490a-9e0e-4edced954498_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_fe61482a-2a12-4877-ad5d-8266aee0d1c9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_aa5f6973-84c5-490a-9e0e-4edced954498" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_fe61482a-2a12-4877-ad5d-8266aee0d1c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_fb7d8360-3208-4add-a415-e1c2bab6031a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_fe61482a-2a12-4877-ad5d-8266aee0d1c9" xlink:to="loc_us-gaap_InterestRateSwapMember_fb7d8360-3208-4add-a415-e1c2bab6031a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_d4a9ce7b-26af-46cf-845d-7dbcc4dbfce7" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ab7705c2-650a-42d1-ace3-713320e628f8" xlink:to="loc_srt_RangeAxis_d4a9ce7b-26af-46cf-845d-7dbcc4dbfce7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_d4a9ce7b-26af-46cf-845d-7dbcc4dbfce7_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_d4a9ce7b-26af-46cf-845d-7dbcc4dbfce7" xlink:to="loc_srt_RangeMember_d4a9ce7b-26af-46cf-845d-7dbcc4dbfce7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_b6fe48d0-11ac-4d48-b401-bad8252fa81b" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_d4a9ce7b-26af-46cf-845d-7dbcc4dbfce7" xlink:to="loc_srt_RangeMember_b6fe48d0-11ac-4d48-b401-bad8252fa81b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_ce83fda2-c316-4eba-8893-8046d3d6a88a" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_b6fe48d0-11ac-4d48-b401-bad8252fa81b" xlink:to="loc_srt_MinimumMember_ce83fda2-c316-4eba-8893-8046d3d6a88a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_849c1137-35a7-4074-b694-f980a4c6b62d" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_b6fe48d0-11ac-4d48-b401-bad8252fa81b" xlink:to="loc_srt_MaximumMember_849c1137-35a7-4074-b694-f980a4c6b62d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_c130e935-14ad-4e97-aac8-e17d6c62399d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ab7705c2-650a-42d1-ace3-713320e628f8" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_c130e935-14ad-4e97-aac8-e17d6c62399d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_c130e935-14ad-4e97-aac8-e17d6c62399d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_c130e935-14ad-4e97-aac8-e17d6c62399d" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_c130e935-14ad-4e97-aac8-e17d6c62399d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4d4636b7-12b0-4d6b-9d1c-cbb07cac47a8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_c130e935-14ad-4e97-aac8-e17d6c62399d" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4d4636b7-12b0-4d6b-9d1c-cbb07cac47a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_b49a0ebb-69bd-410b-97f3-98944eb88f1c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4d4636b7-12b0-4d6b-9d1c-cbb07cac47a8" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_b49a0ebb-69bd-410b-97f3-98944eb88f1c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_98f254c7-11a8-4ac1-ba31-23dd18be16c2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ab7705c2-650a-42d1-ace3-713320e628f8" xlink:to="loc_us-gaap_DebtInstrumentAxis_98f254c7-11a8-4ac1-ba31-23dd18be16c2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_98f254c7-11a8-4ac1-ba31-23dd18be16c2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_98f254c7-11a8-4ac1-ba31-23dd18be16c2" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_98f254c7-11a8-4ac1-ba31-23dd18be16c2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_b9760bf5-8c71-46ab-890e-521a4d222a4c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_98f254c7-11a8-4ac1-ba31-23dd18be16c2" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_b9760bf5-8c71-46ab-890e-521a4d222a4c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignLineOfCreditMember_a559b6b5-9267-4479-b2de-86d96b90344e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignLineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_b9760bf5-8c71-46ab-890e-521a4d222a4c" xlink:to="loc_us-gaap_ForeignLineOfCreditMember_a559b6b5-9267-4479-b2de-86d96b90344e" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/FairValueMeasurementsLiabilitiesMeasureatFairValuePreferredStockDetails" xlink:type="simple" xlink:href="nnbr-20220930.xsd#FairValueMeasurementsLiabilitiesMeasureatFairValuePreferredStockDetails"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/FairValueMeasurementsLiabilitiesMeasureatFairValuePreferredStockDetails" xlink:type="extended" id="iaed7d36aabbe4fc5b13cd48e8855723a_FairValueMeasurementsLiabilitiesMeasureatFairValuePreferredStockDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_a249ca22-1556-40f9-a4cb-167820eb023c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_ef1e8f14-9b87-47f0-ba77-94a363f3bfad" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_a249ca22-1556-40f9-a4cb-167820eb023c" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_ef1e8f14-9b87-47f0-ba77-94a363f3bfad" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_b46ca29c-73c0-4d73-9eac-bf9865c0f641" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_a249ca22-1556-40f9-a4cb-167820eb023c" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_b46ca29c-73c0-4d73-9eac-bf9865c0f641" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_819b6d4b-163e-45f9-bd96-23eab100ecb2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_b46ca29c-73c0-4d73-9eac-bf9865c0f641" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_819b6d4b-163e-45f9-bd96-23eab100ecb2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_819b6d4b-163e-45f9-bd96-23eab100ecb2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_819b6d4b-163e-45f9-bd96-23eab100ecb2" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_819b6d4b-163e-45f9-bd96-23eab100ecb2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_59f29848-af37-451b-9e31-89defc93dfd1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_819b6d4b-163e-45f9-bd96-23eab100ecb2" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_59f29848-af37-451b-9e31-89defc93dfd1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_213aa47c-05f1-4d47-9043-5ddde2b67846" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_59f29848-af37-451b-9e31-89defc93dfd1" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_213aa47c-05f1-4d47-9043-5ddde2b67846" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_b71b84ad-ce50-423a-a0ad-0db2f60dd3b8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_59f29848-af37-451b-9e31-89defc93dfd1" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_b71b84ad-ce50-423a-a0ad-0db2f60dd3b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_91fd91f2-f88f-4f35-bda6-10d2409bebc5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_59f29848-af37-451b-9e31-89defc93dfd1" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_91fd91f2-f88f-4f35-bda6-10d2409bebc5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_a6d08ed1-ced5-45d8-a615-ba92c70fe9f9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_b46ca29c-73c0-4d73-9eac-bf9865c0f641" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_a6d08ed1-ced5-45d8-a615-ba92c70fe9f9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_a6d08ed1-ced5-45d8-a615-ba92c70fe9f9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_a6d08ed1-ced5-45d8-a615-ba92c70fe9f9" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_a6d08ed1-ced5-45d8-a615-ba92c70fe9f9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_461232ef-19a7-4727-bd5e-6dc1c58b9719" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_a6d08ed1-ced5-45d8-a615-ba92c70fe9f9" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_461232ef-19a7-4727-bd5e-6dc1c58b9719" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCurrentLiabilitiesMember_39437f32-0b55-410f-b768-e4540efe3fa8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherCurrentLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_461232ef-19a7-4727-bd5e-6dc1c58b9719" xlink:to="loc_us-gaap_OtherCurrentLiabilitiesMember_39437f32-0b55-410f-b768-e4540efe3fa8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncurrentLiabilitiesMember_42865916-478d-4c74-904e-f4fda6ebfbc1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherNoncurrentLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_461232ef-19a7-4727-bd5e-6dc1c58b9719" xlink:to="loc_us-gaap_OtherNoncurrentLiabilitiesMember_42865916-478d-4c74-904e-f4fda6ebfbc1" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/FairValueMeasurementsEffectofInterestRateSwapDetails" xlink:type="simple" xlink:href="nnbr-20220930.xsd#FairValueMeasurementsEffectofInterestRateSwapDetails"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/FairValueMeasurementsEffectofInterestRateSwapDetails" xlink:type="extended" id="iae5961291fc444219f10c4815a485ef1_FairValueMeasurementsEffectofInterestRateSwapDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_b8bb108c-af98-4269-8dac-0e949b1664f2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_4dac0dc7-df62-467a-97dc-ea4c5a023eef" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_b8bb108c-af98-4269-8dac-0e949b1664f2" xlink:to="loc_us-gaap_InterestExpense_4dac0dc7-df62-467a-97dc-ea4c5a023eef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_DerivativeInstrumentsPaymentExpense_0d9c9961-8a98-4acf-8475-111525c099db" xlink:href="nnbr-20220930.xsd#nnbr_DerivativeInstrumentsPaymentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_b8bb108c-af98-4269-8dac-0e949b1664f2" xlink:to="loc_nnbr_DerivativeInstrumentsPaymentExpense_0d9c9961-8a98-4acf-8475-111525c099db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnDerivativeInstrumentsNetPretax_95a5f1cc-c78a-4f59-b22c-0d5166f9dbe6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainLossOnDerivativeInstrumentsNetPretax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_b8bb108c-af98-4269-8dac-0e949b1664f2" xlink:to="loc_us-gaap_GainLossOnDerivativeInstrumentsNetPretax_95a5f1cc-c78a-4f59-b22c-0d5166f9dbe6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForHedgeInvestingActivities_7e22564d-10c3-400c-a436-4912fc1fd66a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsForHedgeInvestingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_b8bb108c-af98-4269-8dac-0e949b1664f2" xlink:to="loc_us-gaap_PaymentsForHedgeInvestingActivities_7e22564d-10c3-400c-a436-4912fc1fd66a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_11605061-5794-451c-ba4f-d6ec2454191d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_b8bb108c-af98-4269-8dac-0e949b1664f2" xlink:to="loc_us-gaap_DerivativeTable_11605061-5794-451c-ba4f-d6ec2454191d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_8567df03-02a3-4ce1-a55e-ad0ec0e31e29" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_11605061-5794-451c-ba4f-d6ec2454191d" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_8567df03-02a3-4ce1-a55e-ad0ec0e31e29" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_8567df03-02a3-4ce1-a55e-ad0ec0e31e29_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_8567df03-02a3-4ce1-a55e-ad0ec0e31e29" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_8567df03-02a3-4ce1-a55e-ad0ec0e31e29_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_30dade54-4a32-45eb-a5b8-95891c23509d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_8567df03-02a3-4ce1-a55e-ad0ec0e31e29" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_30dade54-4a32-45eb-a5b8-95891c23509d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_f4e095a3-f0e1-4e18-8809-546d62c270a1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_30dade54-4a32-45eb-a5b8-95891c23509d" xlink:to="loc_us-gaap_InterestRateSwapMember_f4e095a3-f0e1-4e18-8809-546d62c270a1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/FairValueMeasurementsInterestRateSwapDetails" xlink:type="simple" xlink:href="nnbr-20220930.xsd#FairValueMeasurementsInterestRateSwapDetails"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/FairValueMeasurementsInterestRateSwapDetails" xlink:type="extended" id="i45669073459448c082688e91199ca3fb_FairValueMeasurementsInterestRateSwapDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_3a62f451-c1ac-4f26-9bca-deef7c256749" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetsCurrent_e8cab304-8dad-4c95-9aea-2fe69b9a6d07" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_3a62f451-c1ac-4f26-9bca-deef7c256749" xlink:to="loc_us-gaap_DerivativeAssetsCurrent_e8cab304-8dad-4c95-9aea-2fe69b9a6d07" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetsNoncurrent_51f20435-2f5a-44f8-87d4-31cf574e328a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_3a62f451-c1ac-4f26-9bca-deef7c256749" xlink:to="loc_us-gaap_DerivativeAssetsNoncurrent_51f20435-2f5a-44f8-87d4-31cf574e328a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilitiesCurrent_b836f841-323c-4bc4-ba62-ce636a95bb5a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_3a62f451-c1ac-4f26-9bca-deef7c256749" xlink:to="loc_us-gaap_DerivativeLiabilitiesCurrent_b836f841-323c-4bc4-ba62-ce636a95bb5a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilitiesNoncurrent_8be3fbe3-d90b-4807-a7b5-f3573d3db1e7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_3a62f451-c1ac-4f26-9bca-deef7c256749" xlink:to="loc_us-gaap_DerivativeLiabilitiesNoncurrent_8be3fbe3-d90b-4807-a7b5-f3573d3db1e7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeNet_ada8103c-d3d2-4f89-8b41-296df319cc45" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_3a62f451-c1ac-4f26-9bca-deef7c256749" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeNet_ada8103c-d3d2-4f89-8b41-296df319cc45" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_e364705f-e995-48bb-8b43-c3b3333759cb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_3a62f451-c1ac-4f26-9bca-deef7c256749" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_e364705f-e995-48bb-8b43-c3b3333759cb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a1894207-fe78-42a5-aff0-ea4e9dd78247" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_e364705f-e995-48bb-8b43-c3b3333759cb" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a1894207-fe78-42a5-aff0-ea4e9dd78247" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a1894207-fe78-42a5-aff0-ea4e9dd78247_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a1894207-fe78-42a5-aff0-ea4e9dd78247" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a1894207-fe78-42a5-aff0-ea4e9dd78247_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_04baa1e7-2ac4-4f2d-ab78-6bb208601e81" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a1894207-fe78-42a5-aff0-ea4e9dd78247" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_04baa1e7-2ac4-4f2d-ab78-6bb208601e81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_09a8c8ca-6123-428d-8cf9-ab98c0c58be6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_04baa1e7-2ac4-4f2d-ab78-6bb208601e81" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_09a8c8ca-6123-428d-8cf9-ab98c0c58be6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_55a72cf8-548e-4caf-badb-466fc34b78d4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_04baa1e7-2ac4-4f2d-ab78-6bb208601e81" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_55a72cf8-548e-4caf-badb-466fc34b78d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_d206d676-e9ef-4819-a443-8bee6fe030cb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_04baa1e7-2ac4-4f2d-ab78-6bb208601e81" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_d206d676-e9ef-4819-a443-8bee6fe030cb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_00e2e284-9885-4dca-ab22-95faaa9da8e5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_e364705f-e995-48bb-8b43-c3b3333759cb" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_00e2e284-9885-4dca-ab22-95faaa9da8e5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_00e2e284-9885-4dca-ab22-95faaa9da8e5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_00e2e284-9885-4dca-ab22-95faaa9da8e5" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_00e2e284-9885-4dca-ab22-95faaa9da8e5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_c01332ad-4e6b-4f16-a328-77ed8086d7eb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_00e2e284-9885-4dca-ab22-95faaa9da8e5" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_c01332ad-4e6b-4f16-a328-77ed8086d7eb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_9518eccd-b6e1-402c-972e-e0d3aec3b6e2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_c01332ad-4e6b-4f16-a328-77ed8086d7eb" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_9518eccd-b6e1-402c-972e-e0d3aec3b6e2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_cbd4bcb0-465c-45ad-9e25-9ff127998296" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_e364705f-e995-48bb-8b43-c3b3333759cb" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_cbd4bcb0-465c-45ad-9e25-9ff127998296" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_cbd4bcb0-465c-45ad-9e25-9ff127998296_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_cbd4bcb0-465c-45ad-9e25-9ff127998296" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_cbd4bcb0-465c-45ad-9e25-9ff127998296_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_6914bdaa-615f-493c-bb37-1f1fb65d37cd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_cbd4bcb0-465c-45ad-9e25-9ff127998296" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_6914bdaa-615f-493c-bb37-1f1fb65d37cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_8dad657d-d786-48cc-ae48-1c21eccce545" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_6914bdaa-615f-493c-bb37-1f1fb65d37cd" xlink:to="loc_us-gaap_InterestRateSwapMember_8dad657d-d786-48cc-ae48-1c21eccce545" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/FairValueMeasurementsNotionalAmountsoftheInterestRateSwapDetails" xlink:type="simple" xlink:href="nnbr-20220930.xsd#FairValueMeasurementsNotionalAmountsoftheInterestRateSwapDetails"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/FairValueMeasurementsNotionalAmountsoftheInterestRateSwapDetails" xlink:type="extended" id="i2b1a257b99224751b2c01fc40dc1dd3a_FairValueMeasurementsNotionalAmountsoftheInterestRateSwapDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_6fa3dac7-1068-42f3-a52a-4a9bc946678b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_2cd03182-9813-461d-a5be-a0ac5027b40e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_6fa3dac7-1068-42f3-a52a-4a9bc946678b" xlink:to="loc_us-gaap_DerivativeNotionalAmount_2cd03182-9813-461d-a5be-a0ac5027b40e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTable_a4cf502c-123a-4a62-bafa-305f36813dc8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_6fa3dac7-1068-42f3-a52a-4a9bc946678b" xlink:to="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTable_a4cf502c-123a-4a62-bafa-305f36813dc8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_10b9ab57-c6df-4e55-aacd-400b1aeb2cde" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTable_a4cf502c-123a-4a62-bafa-305f36813dc8" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_10b9ab57-c6df-4e55-aacd-400b1aeb2cde" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_10b9ab57-c6df-4e55-aacd-400b1aeb2cde_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_10b9ab57-c6df-4e55-aacd-400b1aeb2cde" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_10b9ab57-c6df-4e55-aacd-400b1aeb2cde_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_298c1417-e5f4-47f4-8db3-31a7dacc2c63" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_10b9ab57-c6df-4e55-aacd-400b1aeb2cde" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_298c1417-e5f4-47f4-8db3-31a7dacc2c63" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_InterestRateSwapFebruary122019toDecember302020Member_8ee25acf-f5e0-4111-b59e-3b87ec93ece5" xlink:href="nnbr-20220930.xsd#nnbr_InterestRateSwapFebruary122019toDecember302020Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_298c1417-e5f4-47f4-8db3-31a7dacc2c63" xlink:to="loc_nnbr_InterestRateSwapFebruary122019toDecember302020Member_8ee25acf-f5e0-4111-b59e-3b87ec93ece5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_InterestRateSwapDecember312020toDecember302021Member_65752c27-46f6-41b0-8b06-e771145f6afe" xlink:href="nnbr-20220930.xsd#nnbr_InterestRateSwapDecember312020toDecember302021Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_298c1417-e5f4-47f4-8db3-31a7dacc2c63" xlink:to="loc_nnbr_InterestRateSwapDecember312020toDecember302021Member_65752c27-46f6-41b0-8b06-e771145f6afe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_nnbr_InterestRateSwapDecember312021toOctober192022Member_e0fc6168-106f-4865-8e7b-9bb96a7a8d28" xlink:href="nnbr-20220930.xsd#nnbr_InterestRateSwapDecember312021toOctober192022Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_298c1417-e5f4-47f4-8db3-31a7dacc2c63" xlink:to="loc_nnbr_InterestRateSwapDecember312021toOctober192022Member_e0fc6168-106f-4865-8e7b-9bb96a7a8d28" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.nninc.com/role/SubsequentEventsDetails" xlink:type="simple" xlink:href="nnbr-20220930.xsd#SubsequentEventsDetails"/>
  <link:definitionLink xlink:role="http://www.nninc.com/role/SubsequentEventsDetails" xlink:type="extended" id="icc08b525e7ed4ab8b59e22206bb9d2cd_SubsequentEventsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_3e816d8c-25e3-4321-9c31-5baa5fae3284" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_acabc292-c508-4667-8985-ca82e48d0f9c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_3e816d8c-25e3-4321-9c31-5baa5fae3284" xlink:to="loc_us-gaap_SubsequentEventTable_acabc292-c508-4667-8985-ca82e48d0f9c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_ec2d902b-ccfb-4d7f-9bee-5f16e222a05a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_acabc292-c508-4667-8985-ca82e48d0f9c" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_ec2d902b-ccfb-4d7f-9bee-5f16e222a05a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_ec2d902b-ccfb-4d7f-9bee-5f16e222a05a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_ec2d902b-ccfb-4d7f-9bee-5f16e222a05a" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_ec2d902b-ccfb-4d7f-9bee-5f16e222a05a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_6fceba9b-a5f2-4b93-a52a-473a10dbfd4a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_ec2d902b-ccfb-4d7f-9bee-5f16e222a05a" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_6fceba9b-a5f2-4b93-a52a-473a10dbfd4a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_5d1f2666-2c76-41ec-9ce0-7331d6671483" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_acabc292-c508-4667-8985-ca82e48d0f9c" xlink:to="loc_us-gaap_CreditFacilityAxis_5d1f2666-2c76-41ec-9ce0-7331d6671483" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_5d1f2666-2c76-41ec-9ce0-7331d6671483_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_5d1f2666-2c76-41ec-9ce0-7331d6671483" xlink:to="loc_us-gaap_CreditFacilityDomain_5d1f2666-2c76-41ec-9ce0-7331d6671483_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_8c8eb5e7-03fd-479e-a676-68072c633772" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_5d1f2666-2c76-41ec-9ce0-7331d6671483" xlink:to="loc_us-gaap_CreditFacilityDomain_8c8eb5e7-03fd-479e-a676-68072c633772" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_cff5ecf5-518c-4214-93cd-2eb47b51fa9a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_acabc292-c508-4667-8985-ca82e48d0f9c" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_cff5ecf5-518c-4214-93cd-2eb47b51fa9a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_cff5ecf5-518c-4214-93cd-2eb47b51fa9a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_cff5ecf5-518c-4214-93cd-2eb47b51fa9a" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_cff5ecf5-518c-4214-93cd-2eb47b51fa9a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_5935fc41-9428-44ce-bf65-fa1a4f06a6c4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_cff5ecf5-518c-4214-93cd-2eb47b51fa9a" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_5935fc41-9428-44ce-bf65-fa1a4f06a6c4" xlink:type="arc" order="1"/>
  </link:definitionLink>
</link:linkbase>
