UNFA'ITHFUL, adjective 1. Not observant of promises, vows, allegiance or duty; violating trust or confidence; treacherous; perfidious; as an unfaithful subject; an unfaithful husband or wife; an unfaithful servant; an unfaithful bailee or agent. 2. Not performing the proper duty. My feet through wine unfaithful to their weight - 3. Impious; infidel. 4. Negligent of duty; as an unfaithful workman.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI