not faithful; false to duty, obligation, or promises; faithless; disloyal.

not sexually faithful to a spouse or lover.

not accurate or complete; inexact

an unfaithful translation.

Obsolete . unbelieving; infidel.

adjective

faithful , loyal , trustworthy

adjective

adulterine , cheating , deceitful , double-crossing , faithless , false , false-hearted , fickle , foresworn , inconstant , incontinent , moonlighting , not true to , of bad faith , perfidious , philandering , recreant , shifty * , snaky * , sneaking , traitorous , treacherous , treasonable , two-faced * , two-timing , unchaste , unreliable , untrue , untrustworthy , wicked , disloyal , adulterous , apostate , derelict , dishonest , inaccurate , infidel , pervert , renegade , undutiful , unloyal , unsteadfast