TOEFL strengthen Definition To make or become stronger in power, quality, or degree. Example "Daily exercise can strengthen your immune system." Sign in to save TOEFL Quiz → ← streak strenuous → Study tips featuring "strengthen" Map Each Word Into a Connected Network Track How TOEFL Words Behave With Others Group TOEFL Words Around Academic Themes Related words TOEFL brighten GRE abash GRE abate GRE abbreviate GRE abbreviation SAT abdicate GRE abduct SAT abet GRE abhor GRE abide SAT abject TOEFL ablaze