n. 25B6; noun UNFAITHFULNESS, adultery, unchastity; faithlessness, disloyalty, treachery, double-dealing, duplicity, deceit; affair; informal playing around, fooling around, cheating, two-timing; formal fornication; dated cuckoldry.
INFIDELITY
Meaning of INFIDELITY in English
Concise Oxford thesaurus English vocabulary. Краткий оксфордский словарь английского языка тезаурус. 2012