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