1. (n.) Unfaithfulness to the marriage vow; disloyalty\.

2. (n.) Want of faith or belief in some religious system; especially, a want of faith in, or disbelief of, the inspiration of the Scriptures, of the divine origin of Christianity.

3. (n.) Breach of trust; unfaithfulness to a charge, or to moral obligation; treachery; deceit; as, the infidelity of a servant.

Punic faith adulterous affair adultery affair agnosticism amor amour apostasy atheism bad faith barratry breach of faith breach of promise breach of trust cheating cuckoldry denial dereliction disaffection disbelief discredit disloyalty entanglement eternal triangle faithlessness falseness falsity fickleness flirtation forbidden love gentilism hanky-panky heresy illicit love inability to believe inconstancy incredulity intrigue liaison love affair mala fides minimifidianism misbelief nonbelief nullifidianism perfidy recreancy rejection romance romantic tie secularism traitorousness treachery triangle trothlessness unbelief unbelievingness unfaith unfaithfulness unloyalty unsteadfastness untrueness