Here's what rhymes with spontaneity.
deity dubiety homogeneity heterogeneity simultaneity contemporaneity Words that almost rhyme with spontaneity
fealty uneasily aridity realty naivety peony legally obesity unequally unevenly ideality benignity reapply regally cheekily needfully sneakily wheezily anemically recently secrecy speedily agreeably decency illegally peacefully decently greedily needlessly peaceably regency zealously dreamily gleefully serenely unbelievably genially piquancy sleepily deceitfully drearily obscenely breezily feasibly phonemically believably greasily heedfully piquantly creakily creepily queasily creamily sleazily appreciably conceivably ceaselessly grievously indecency leniency unspeakably facetiously heedlessly leniently seamlessly indecently congenially speciously covetously conceitedly coequally squeakily frequency frequently conveniently supremely historicity ingeniously unfrequently coherently crystallinity disagreeably inconceivably egregiously irredeemably speechlessly inappreciably indefeasibly sleeplessly unrelievedly infrequently irretrievably inconveniently infrequency heterogeneously centripetally