Here's what rhymes with fastingly.
lastingly everlastingly Words that almost rhyme with fastingly
actively passingly slantingly drastically passively tacitly savagely laughingly massively statically validly apically exactingly radically emphatically sanctity veracity amity classically lavishly sarcastically fantastically handedly placidly thematically erratically slavishly enchantingly scholastically snappishly inactively irascibly waggishly monastically mannishly raffishly caddishly prancingly graphically candidly schematically sporadically tragically attractively casuistry panicky ecstatically proactively impassively pneumatically invalidly bombastically unflaggingly operatically abashedly gymnastically rheumatically automatically dramatically enthusiastically mechanically dynamically tenacity organically dogmatically distractedly interactively outstandingly venality climatically ecclesiastically expansively chromatically offhandedly phlegmatically aromatically highhandedly humanity systematically plurality centrality immorality banality bestiality mendacity nostalgically pugnacity retroactively unabashedly enigmatically radioactively autocratically axiomatically idiomatically thermostatically outlandishly unattractively acrobatically personality rationality democratically illegality diplomatically informality pertinacity speciality photographically seasonality understandingly ethnographically symptomatically biographically emblematically orthographically telepathically aristocratically evenhandedly inorganically lithographically underhandedly immortality originality temporality emotionality eventuality topographically bureaucratically demographically problematically aerodynamically typographically telegraphically functionality impartiality criminality materiality mutuality principality artificiality marginality punctuality superficiality collegiality technicality idiosyncratically melodramatically pornographically individuality intentionality immateriality autobiographically bibliographically proportionality sentimentality conventionality instrumentality constitutionality heterosexuality unconventionality unconstitutionality