V-RECIP
(男女未婚而)同居，姘居
If two people are cohabiting, they are living together and have a sexual relationship, but are not married.
例句
In Italy people hardly ever cohabit...
在意大利，很少有人未婚同居。
The dentist left his wife of 15 years and openly cohabited with his receptionist...
那个牙医离开了和他生活了15年的妻子，与自己诊所的接待小姐公开同居。