marital disloyalty; adultery.

unfaithfulness; disloyalty.

lack of religious faith, esp. Christian faith.

a breach of trust or a disloyal act; transgression.

noun

faithfulness , fidelity , loyalty

noun

adultery , affair , bad faith , betrayal , cheating , duplicity , extramarital relations , faithlessness , falseness , falsity , inconstancy , lewdness , perfidiousness , perfidy , treacherousness , treachery , treason , two-timing , unfaithfulness , disloyalty , false-heartedness , traitorousness , breach , violation