cohabit
verb [intransitive] (formal)- cohabit (with somebody)
(usually of a man and a woman )通常指男女 to live together and have a sexual relationship without being married (无婚姻关系)同居 cohabiting couples 同居伴侣 She refused to cohabit with him before the wedding. 她拒绝在婚礼前和他同居。
Word Originmid 16th cent.: from Latin cohabitare, from co- ‘together’ + habitare ‘dwell’.