Here's what rhymes with vainfully.
painfully gainfully disdainfully Words that almost rhyme with vainfully
shamefully faithfully fatefully hatefully hastily fatally daintily shakily balefully facially hazily heinously wakefully shadily gracefully gratefully racially spatially anciently famously playfully tastefully painlessly wastefully nasally weightily cagily faithlessly tastily unfaithfully changeably racily shapelessly agelessly agency vacancy gaiety laity papacy aimlessly shamelessly vagrancy crazily matronly capably nakedly glacially spaciously ashamedly throatily weightlessly brainlessly masonry patiently graciously latency courageously brazenly disgracefully flagrantly voraciously audaciously ungratefully insatiably vivaciously cravenly distastefully fallaciously ungracefully unshakably elatedly flagrancy fragrantly gracelessly tastelessly unshakeably namelessly salaciously salacity palatially mistakenly tenaciously belatedly blatantly outrageously adjacency unashamedly efficaciously prenatally blamelessly flirtatiously vexatiously adjacently blatancy capaciously incapably impatiently interchangeably inescapably tetralogy freemasonry ungraciously contagiously mendaciously loquaciously unmistakably advantageously interagency ostentatiously organizationally pertinaciously organisationally perspicaciously complacency complacently computationally complaisantly disputatiously quantitatively calculatedly disadvantageously