for ‧ ni ‧ cate /ˈfɔːnəkeɪt, ˈfɔːnɪkeɪt $ ˈfɔːr-/ BrE AmE verb [intransitive]
[ Date: 1500-1600 ; Language: Late Latin ; Origin: fornicare , from Latin fornix 'brothel (= place for buying sex)' ]
a word meaning to have sex with someone who you are not married to – used to show strong disapproval
—fornication /ˌfɔːnəˈkeɪʃ ə n, ˌfɔːnɪˈkeɪʃ ə n $ ˌfɔːr-/ noun [uncountable]