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