King James Bible

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.