informal dated Live together as though married.
More example sentences
- Back when my wife and I were college room-mates living in sin, we had a cockatiel that really, really liked her.
- It was perhaps more of a stigma for the children that mother was living in sin than it was for the parents.
- A great idea for anyone who, like me, is getting married but has been living in sin for years and so has a bottom drawer full of towels, bedding, frying pans and cut glass.
Definition of live in sin in:
- The British & World English dictionary