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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019f1e0a-c21b-76f5-8ca8-85aa07af619a,g:d023417e-5168-422a-85f2-2b77a95ec870-->
<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://xbrl.sec.gov/oef/role/SeriesOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#SeriesOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/oef/role/SeriesOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_S000006182Member_019f1e0a-c21b-7c73-bcc8-d7b633027864" xlink:href="ck0001131042-20260729.xsd#ck0001131042_S000006182Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain" xlink:to="loc_ck0001131042_S000006182Member_019f1e0a-c21b-7c73-bcc8-d7b633027864" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_S000006183Member_019f1e0a-c21b-7a92-81ea-1c25123ea7fd" xlink:href="ck0001131042-20260729.xsd#ck0001131042_S000006183Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain" xlink:to="loc_ck0001131042_S000006183Member_019f1e0a-c21b-7a92-81ea-1c25123ea7fd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_S000006185Member_019f1e0a-c21b-7ebe-bbaa-680e8509949c" xlink:href="ck0001131042-20260729.xsd#ck0001131042_S000006185Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain" xlink:to="loc_ck0001131042_S000006185Member_019f1e0a-c21b-7ebe-bbaa-680e8509949c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_S000006186Member_019f1e0a-c21b-724d-b4ea-3c0b4d3ec4b7" xlink:href="ck0001131042-20260729.xsd#ck0001131042_S000006186Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain" xlink:to="loc_ck0001131042_S000006186Member_019f1e0a-c21b-724d-b4ea-3c0b4d3ec4b7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_S000006189Member_019f1e0a-c21b-7c90-b494-657fbd7017bb" xlink:href="ck0001131042-20260729.xsd#ck0001131042_S000006189Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain" xlink:to="loc_ck0001131042_S000006189Member_019f1e0a-c21b-7c90-b494-657fbd7017bb" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/rr/role/ProspectusOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#ProspectusOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/rr/role/ProspectusOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentDomain" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_ServiceSharesProspectusMember_019f1e0a-c21b-7868-ad5d-ec146ba9f3e8" xlink:href="ck0001131042-20260729.xsd#ck0001131042_ServiceSharesProspectusMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentDomain" xlink:to="loc_ck0001131042_ServiceSharesProspectusMember_019f1e0a-c21b-7868-ad5d-ec146ba9f3e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_RSSharesProspectusMember_019f1e0a-c21b-7e59-97b3-c842daf09b83" xlink:href="ck0001131042-20260729.xsd#ck0001131042_RSSharesProspectusMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentDomain" xlink:to="loc_ck0001131042_RSSharesProspectusMember_019f1e0a-c21b-7e59-97b3-c842daf09b83" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/oef/role/ClassOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#ClassOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/oef/role/ClassOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_oef_ShareClassDomain" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#oef_ShareClassDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_C000017030Member_019f1e0a-c21b-7a8f-bf0e-be1d7192c493" xlink:href="ck0001131042-20260729.xsd#ck0001131042_C000017030Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_ShareClassDomain" xlink:to="loc_ck0001131042_C000017030Member_019f1e0a-c21b-7a8f-bf0e-be1d7192c493" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_C000017031Member_019f1e0a-c21b-7482-bde2-d7f630191e56" xlink:href="ck0001131042-20260729.xsd#ck0001131042_C000017031Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_ShareClassDomain" xlink:to="loc_ck0001131042_C000017031Member_019f1e0a-c21b-7482-bde2-d7f630191e56" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_C000017033Member_019f1e0a-c21b-7080-98de-97e388df202c" xlink:href="ck0001131042-20260729.xsd#ck0001131042_C000017033Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_ShareClassDomain" xlink:to="loc_ck0001131042_C000017033Member_019f1e0a-c21b-7080-98de-97e388df202c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_C000017034Member_019f1e0a-c21b-761d-8908-eb8a29c3510b" xlink:href="ck0001131042-20260729.xsd#ck0001131042_C000017034Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_ShareClassDomain" xlink:to="loc_ck0001131042_C000017034Member_019f1e0a-c21b-761d-8908-eb8a29c3510b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_C000017037Member_019f1e0a-c21b-7694-a601-0269c93fa98a" xlink:href="ck0001131042-20260729.xsd#ck0001131042_C000017037Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_ShareClassDomain" xlink:to="loc_ck0001131042_C000017037Member_019f1e0a-c21b-7694-a601-0269c93fa98a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_C000270753Member_019f1e0a-c21b-7114-a490-ec397e0e4d37" xlink:href="ck0001131042-20260729.xsd#ck0001131042_C000270753Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_ShareClassDomain" xlink:to="loc_ck0001131042_C000270753Member_019f1e0a-c21b-7114-a490-ec397e0e4d37" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_C000270754Member_019f1e0a-c21b-7246-a1b6-61af1466316f" xlink:href="ck0001131042-20260729.xsd#ck0001131042_C000270754Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_ShareClassDomain" xlink:to="loc_ck0001131042_C000270754Member_019f1e0a-c21b-7246-a1b6-61af1466316f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_C000270755Member_019f1e0a-c21b-70e7-92a3-8bfe399633f3" xlink:href="ck0001131042-20260729.xsd#ck0001131042_C000270755Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_ShareClassDomain" xlink:to="loc_ck0001131042_C000270755Member_019f1e0a-c21b-70e7-92a3-8bfe399633f3" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_C000270756Member_019f1e0a-c21b-78ff-b687-ea5b2699ccb5" xlink:href="ck0001131042-20260729.xsd#ck0001131042_C000270756Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_ShareClassDomain" xlink:to="loc_ck0001131042_C000270756Member_019f1e0a-c21b-78ff-b687-ea5b2699ccb5" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_C000270757Member_019f1e0a-c21b-74b5-aebb-331fe346874b" xlink:href="ck0001131042-20260729.xsd#ck0001131042_C000270757Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_ShareClassDomain" xlink:to="loc_ck0001131042_C000270757Member_019f1e0a-c21b-74b5-aebb-331fe346874b" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/rr/role/RiskOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#RiskOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/rr/role/RiskOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_oef_AllRisksMember" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#oef_AllRisksMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_ManagementRiskMember_019f1e0a-c21b-7137-9d39-6883d71198a4" xlink:href="ck0001131042-20260729.xsd#ck0001131042_ManagementRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_ManagementRiskMember_019f1e0a-c21b-7137-9d39-6883d71198a4" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_MarketRiskMember_019f1e0a-c21b-7662-bb3e-b3fe3b2f15ca" xlink:href="ck0001131042-20260729.xsd#ck0001131042_MarketRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_MarketRiskMember_019f1e0a-c21b-7662-bb3e-b3fe3b2f15ca" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_GrowthInvestmentRiskMember_019f1e0a-c21b-79ac-ad5a-0c78a5619fa7" xlink:href="ck0001131042-20260729.xsd#ck0001131042_GrowthInvestmentRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_GrowthInvestmentRiskMember_019f1e0a-c21b-79ac-ad5a-0c78a5619fa7" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_EquityRiskMember_019f1e0a-c21b-7869-afdf-a14013fdb22a" xlink:href="ck0001131042-20260729.xsd#ck0001131042_EquityRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_EquityRiskMember_019f1e0a-c21b-7869-afdf-a14013fdb22a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_ValueInvestmentRiskMember_019f1e0a-c21b-7856-9285-86ae66285fa5" xlink:href="ck0001131042-20260729.xsd#ck0001131042_ValueInvestmentRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_ValueInvestmentRiskMember_019f1e0a-c21b-7856-9285-86ae66285fa5" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_QuantitativeInvestmentTechniquesRiskMember_019f1e0a-c21b-7e1e-8816-1acf266ae16b" xlink:href="ck0001131042-20260729.xsd#ck0001131042_QuantitativeInvestmentTechniquesRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_QuantitativeInvestmentTechniquesRiskMember_019f1e0a-c21b-7e1e-8816-1acf266ae16b" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_InformationTechnologySectorRiskMember_019f1e0a-c21b-755d-880c-2bf55e81b2e7" xlink:href="ck0001131042-20260729.xsd#ck0001131042_InformationTechnologySectorRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_InformationTechnologySectorRiskMember_019f1e0a-c21b-755d-880c-2bf55e81b2e7" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_DerivativesRiskMember_019f1e0a-c21b-7ea3-86ff-81fa5f5f313a" xlink:href="ck0001131042-20260729.xsd#ck0001131042_DerivativesRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_DerivativesRiskMember_019f1e0a-c21b-7ea3-86ff-81fa5f5f313a" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_SecuritiesLendingRiskMember_019f1e0a-c21b-765d-8f74-7b4d748688c8" xlink:href="ck0001131042-20260729.xsd#ck0001131042_SecuritiesLendingRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_SecuritiesLendingRiskMember_019f1e0a-c21b-765d-8f74-7b4d748688c8" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_EmergingMarketsRiskMember_019f1e0a-c21b-715f-b9db-ba6a0443651f" xlink:href="ck0001131042-20260729.xsd#ck0001131042_EmergingMarketsRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_EmergingMarketsRiskMember_019f1e0a-c21b-715f-b9db-ba6a0443651f" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_RegionalRiskMember_019f1e0a-c21b-7eba-b6c2-0d8133a8b3cd" xlink:href="ck0001131042-20260729.xsd#ck0001131042_RegionalRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_RegionalRiskMember_019f1e0a-c21b-7eba-b6c2-0d8133a8b3cd" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_ForeignSecuritiesRiskMember_019f1e0a-c21b-7f07-8797-e4abab58be34" xlink:href="ck0001131042-20260729.xsd#ck0001131042_ForeignSecuritiesRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_ForeignSecuritiesRiskMember_019f1e0a-c21b-7f07-8797-e4abab58be34" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_CurrencyRiskMember_019fa9fe-544e-7a5f-8181-c59526fc73a3" xlink:href="ck0001131042-20260729.xsd#ck0001131042_CurrencyRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_CurrencyRiskMember_019fa9fe-544e-7a5f-8181-c59526fc73a3" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_SmallAndMediumCapitalizationCompanyRiskMember_019f1e0a-c21b-7e33-bd50-d2168b9fea53" xlink:href="ck0001131042-20260729.xsd#ck0001131042_SmallAndMediumCapitalizationCompanyRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_SmallAndMediumCapitalizationCompanyRiskMember_019f1e0a-c21b-7e33-bd50-d2168b9fea53" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_LiquidityRiskMember_019f1e0a-c21b-75bc-a478-309191ced48c" xlink:href="ck0001131042-20260729.xsd#ck0001131042_LiquidityRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_LiquidityRiskMember_019f1e0a-c21b-75bc-a478-309191ced48c" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_ExchangeTradedFundsRiskMember_019f1e0a-c21b-77c8-9130-76167805ade6" xlink:href="ck0001131042-20260729.xsd#ck0001131042_ExchangeTradedFundsRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_ExchangeTradedFundsRiskMember_019f1e0a-c21b-77c8-9130-76167805ade6" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_FinancialsSectorRiskMember_019f1e0a-c21b-707c-837e-6316025d1091" xlink:href="ck0001131042-20260729.xsd#ck0001131042_FinancialsSectorRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_FinancialsSectorRiskMember_019f1e0a-c21b-707c-837e-6316025d1091" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_PortfolioTurnoverRiskMember_019f1e0a-c21b-725c-83d3-30676540df19" xlink:href="ck0001131042-20260729.xsd#ck0001131042_PortfolioTurnoverRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_PortfolioTurnoverRiskMember_019f1e0a-c21b-725c-83d3-30676540df19" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_InterestRateRisk1Member_019f1e0a-c21b-795a-a710-4aee9c222d97" xlink:href="ck0001131042-20260729.xsd#ck0001131042_InterestRateRisk1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_InterestRateRisk1Member_019f1e0a-c21b-795a-a710-4aee9c222d97" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_MortgageAndAssetBackedSecuritiesRiskMember_019f1e0a-c21b-7c86-9b88-5f228a33ad19" xlink:href="ck0001131042-20260729.xsd#ck0001131042_MortgageAndAssetBackedSecuritiesRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_MortgageAndAssetBackedSecuritiesRiskMember_019f1e0a-c21b-7c86-9b88-5f228a33ad19" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_DebtFixedIncomeSecuritiesRiskMember_019f1e0a-c21b-7a07-9658-f9adb7170a03" xlink:href="ck0001131042-20260729.xsd#ck0001131042_DebtFixedIncomeSecuritiesRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_DebtFixedIncomeSecuritiesRiskMember_019f1e0a-c21b-7a07-9658-f9adb7170a03" xlink:type="arc" order="29"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_CreditRisk1Member_019f1e0a-c21b-7c00-a53a-0285b0ea51a7" xlink:href="ck0001131042-20260729.xsd#ck0001131042_CreditRisk1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_CreditRisk1Member_019f1e0a-c21b-7c00-a53a-0285b0ea51a7" xlink:type="arc" order="30"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_TaxRiskInflationIndexedSecuritiesMember_019f1e0a-c21b-740c-a58d-f1cf75d58a51" xlink:href="ck0001131042-20260729.xsd#ck0001131042_TaxRiskInflationIndexedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_TaxRiskInflationIndexedSecuritiesMember_019f1e0a-c21b-740c-a58d-f1cf75d58a51" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_U.S.GovernmentAgencyObligationsRiskMember_019f1e0a-c21b-7d52-b839-9fae16bd8175" xlink:href="ck0001131042-20260729.xsd#ck0001131042_U.S.GovernmentAgencyObligationsRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_U.S.GovernmentAgencyObligationsRiskMember_019f1e0a-c21b-7d52-b839-9fae16bd8175" xlink:type="arc" order="32"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_InflationIndexedSecuritiesRiskMember_019f1e0a-c21b-7bcd-9145-ef4fbd6bc8a6" xlink:href="ck0001131042-20260729.xsd#ck0001131042_InflationIndexedSecuritiesRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_InflationIndexedSecuritiesRiskMember_019f1e0a-c21b-7bcd-9145-ef4fbd6bc8a6" xlink:type="arc" order="33"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_MaturityRiskMember_019f1e0a-c21b-76c1-a686-a1fada9ff5a6" xlink:href="ck0001131042-20260729.xsd#ck0001131042_MaturityRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_MaturityRiskMember_019f1e0a-c21b-76c1-a686-a1fada9ff5a6" xlink:type="arc" order="34"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_VariableRateSecuritiesRiskMember_019f1e0a-c21b-7ad1-9d4f-57eb4c050bde" xlink:href="ck0001131042-20260729.xsd#ck0001131042_VariableRateSecuritiesRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_VariableRateSecuritiesRiskMember_019f1e0a-c21b-7ad1-9d4f-57eb4c050bde" xlink:type="arc" order="35"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_CollateralizedDebtObligationsRiskMember_019f1e0a-c21b-7dae-b760-e44a75a01a7d" xlink:href="ck0001131042-20260729.xsd#ck0001131042_CollateralizedDebtObligationsRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_CollateralizedDebtObligationsRiskMember_019f1e0a-c21b-7dae-b760-e44a75a01a7d" xlink:type="arc" order="36"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_ExtensionRiskMember_019f1e0a-c21b-7de6-94d0-d6494727c98b" xlink:href="ck0001131042-20260729.xsd#ck0001131042_ExtensionRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_AllRisksMember" xlink:to="loc_ck0001131042_ExtensionRiskMember_019f1e0a-c21b-7de6-94d0-d6494727c98b" xlink:type="arc" order="37"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/rr/role/PerformanceMeasureOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#PerformanceMeasureOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/rr/role/PerformanceMeasureOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_oef_PerformanceMeasureDomain" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#oef_PerformanceMeasureDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_Russell1000IndexreflectsnodeductionforfeesexpenseortaxesIndexMember_019f1e0a-c21b-77b2-b2de-1da3736e20a5" xlink:href="ck0001131042-20260729.xsd#ck0001131042_Russell1000IndexreflectsnodeductionforfeesexpenseortaxesIndexMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_PerformanceMeasureDomain" xlink:to="loc_ck0001131042_Russell1000IndexreflectsnodeductionforfeesexpenseortaxesIndexMember_019f1e0a-c21b-77b2-b2de-1da3736e20a5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_Russell3000IndexreflectsnodeductionforfeesexpensesortaxesIndexMember_019f1e0a-c21b-708c-9172-33c71212e93f" xlink:href="ck0001131042-20260729.xsd#ck0001131042_Russell3000IndexreflectsnodeductionforfeesexpensesortaxesIndexMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_PerformanceMeasureDomain" xlink:to="loc_ck0001131042_Russell3000IndexreflectsnodeductionforfeesexpensesortaxesIndexMember_019f1e0a-c21b-708c-9172-33c71212e93f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_MSCIEmergingMarketsIndexreflectsnodeductionforfeesexpensesortaxesIndexMember_019f1e0a-c21b-70c0-b015-e9fd2f5dfebf" xlink:href="ck0001131042-20260729.xsd#ck0001131042_MSCIEmergingMarketsIndexreflectsnodeductionforfeesexpensesortaxesIndexMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_PerformanceMeasureDomain" xlink:to="loc_ck0001131042_MSCIEmergingMarketsIndexreflectsnodeductionforfeesexpensesortaxesIndexMember_019f1e0a-c21b-70c0-b015-e9fd2f5dfebf" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_Russell2500IndexreflectsnodeductionforfeesexpensesortaxesMember_019f1e0a-c21b-7cc4-8d3b-f040e96278a5" xlink:href="ck0001131042-20260729.xsd#ck0001131042_Russell2500IndexreflectsnodeductionforfeesexpensesortaxesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_PerformanceMeasureDomain" xlink:to="loc_ck0001131042_Russell2500IndexreflectsnodeductionforfeesexpensesortaxesMember_019f1e0a-c21b-7cc4-8d3b-f040e96278a5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_MSCIWorldexUSAIndexreflectsnodeductionforfeesexpensesortaxesIndexMember_019f1e0a-c21b-78da-94ff-570fa10ebd1a" xlink:href="ck0001131042-20260729.xsd#ck0001131042_MSCIWorldexUSAIndexreflectsnodeductionforfeesexpensesortaxesIndexMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_PerformanceMeasureDomain" xlink:to="loc_ck0001131042_MSCIWorldexUSAIndexreflectsnodeductionforfeesexpensesortaxesIndexMember_019f1e0a-c21b-78da-94ff-570fa10ebd1a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001131042_BloombergU.S.AggregateBondIndexreflectsnodeductionforfeesexpensesortaxesIndexMember_019f1e0a-c21b-760c-baec-0ae688d5aa19" xlink:href="ck0001131042-20260729.xsd#ck0001131042_BloombergU.S.AggregateBondIndexreflectsnodeductionforfeesexpensesortaxesIndexMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oef_PerformanceMeasureDomain" xlink:to="loc_ck0001131042_BloombergU.S.AggregateBondIndexreflectsnodeductionforfeesexpensesortaxesIndexMember_019f1e0a-c21b-760c-baec-0ae688d5aa19" xlink:type="arc" order="8"/>
  </link:definitionLink>
</link:linkbase>
