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