Unfaithful

[ʌn'feɪθfʊl;-f(ə)l] or [ʌn'feθfl]

Definition

(adj.) not trustworthy; 'an unfaithful reproduction' .

(adj.) not true to duty or obligation or promises; 'an unfaithful lover' .

(adj.) having sexual relations with someone other than your husband or wife, or your boyfriend or girlfriend; 'her husband was unfaithful' .

Edited by Amber--From WordNet

Definition

(a.) 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.

(a.) Not possessing faith; infidel.

Checked by Elaine

Synonyms and Synonymous

a. Faithless, treacherous, perfidious, unreliable, derelict, false, deceitful, disloyal, recreant, treasonable, undutiful, false-hearted.

Checked by Kenneth