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