cohabit
verb [ I ] formal uk/kəʊˈhæb.ɪt/ us/koʊˈhæb.ɪt/
（尤指未婚男女）同居
If two people, especially a man and woman who are not married, cohabit, they live together and have a sexual relationship.
About 23 percent of men and women aged 25 to 34 told researchers they had previously cohabited with a partner without it leading to marriage. 年龄在25至34岁之间的男女约有23%的人告诉研究者，他们有过同居而最终没有结婚的经历。
cohabiting couples 同居伴侣