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