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