faithless

not true in one's allegiance to someone or something faithless friends who deserted him in his time of need Synonyms disloyal, false, fickle, inconstant, perfidious, recreant, traitorous, treacherous, unfaithful, untrue Related Words irresponsible, trustless, undependable, unreliable, untrustworthy; faltering, hesitant, vacillating, wavering; dubious, irresolute, uncertain; apathetic, dispassionate, uninterested Near Antonyms dependable, dutiful, reliable, responsible, solid, tried, tried-and-true, trustable, trustworthy, trusty; unfaltering, unhesitating, unwavering; determined, intent, resolute; confirmed, dyed-in-the-wool, inveterate, sworn; ardent, avid, enthusiastic, fervent, fervid, impassioned, passionate Antonyms constant, dedicated, devoted, devout, down-the-line, faithful, fast, loyal, staunch (also stanch), steadfast, steady, true