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