sitting tenant
noun [ C ] UK uk/ˌsɪt.ɪŋ ˈten.ənt/ us/ˌsɪt̬.ɪŋ ˈten.ənt/
（有合法权利的）现有房客，现租户
a person with a legal right to stay in a property that they are renting
We can't sell the house because we can't get rid of the sitting tenants. 我们无法卖房，因为我们打发不掉正在租住的房客。