Here's what rhymes with oversimplify.
high thy vi hi shy sigh fi hy thigh vie psi hai cy fy sy thei phi by my why die lie y buy fly sky guy rely tie bi bye chi defy dye nigh pi pie simplify spy thai dei fry ly quae rye sly ty wir awry lye mai muy nai wry kai lai luy mei tai wai sty stye gentrify slier dry try cry reply deny ply amplify nullify pry tri trie beautify belie pri pupae terrify mollify mortify vilify bonsai deify spry triply blowfly turfy lanai prettify vitrify ripply banzais yuppify apply supply thereby imply nearby whereby hereby modify verify exemplify notify purify alibi fortify pacify ratify unify decry termini typify untie descry edify liquefy overlie ramify acidify aquae ossify retry ultrahigh vivify amebae emulsify horrify petrify stupefy liquify scurfy barfly mummify shanghai drachmai overbuy identify justify occupy satisfy stimuli clarify nuclei qualify specify alkali classify signify testify butterfly certify glorify goodbye gratify intensify quantify underlie magnify rectify samurai falsify indemnify lullaby solidify amoebae codify crucify dignify resupply electrify firefly mystify stratify stultify calcify misapply reunify revivify overfly scarify versify beatify refortify speechify syllabify dandify solemnify comply multiply alveoli diversify standby objectify oversupply personify demystify dragonfly reclassify dissatisfy declassify disqualify detoxify preoccupy cumuli hyperbolae misidentify transmogrify