adultery
/əˈdʌlt(ə)ri
/noun [mass noun]
Voluntary sexual intercourse between a married person and a person who is not their spouse: she was committing adultery with a much younger man...
- You could hook up with someone else, but that would be adultery and adultery is wrong.
- The marriage has to be consummated before an extramarital affair becomes adultery.
- However, it has been held that the petitioner need not find it intolerable to live with the respondent because of his adultery.
Synonyms
unfaithfulness, infidelity, falseness, disloyalty, unchastity, cuckoldry, extramarital sex, extramarital relations;
affair, liaison, intrigue, amour, entanglement, flirtation
informal cheating, two-timing, fooling around, playing around, playing the field, carryings-on, hanky-panky, a bit on the side
formal fornication
Origin
Late 15th century: from the obsolete noun adulter, from Latin adulter 'adulterer', replacing an earlier form avoutrie, from Old French avouterie.