- Not faithful; not observant of promises, vows,
allegiance, or duty; violating trust or confidence; treacherous;
perfidious; as, an unfaithful subject; an unfaithful agent or servant. - Not possessing faith; infidel.
Meaning of 'unfaithful' (Princeton's WordNet)
1 . unfaithful
[ a]
Meaning (1): - not true to duty or obligation or promises
Example in sentence:
an unfaithful lover
Meaning (2): - having sexual relations with someone other than your husband or wife, or your boyfriend or girlfriend
Example in sentence:
her husband was unfaithful
3 . unfaithful
[ s]
Meaning (3): - having the character of, or characteristic of, a traitor