[n] [en] Mistress of a married man. Abode of the mistress of a married man. The boyfriend of a married woman can also be referred to as such.

E.g. 1. He is always with his small house these days.

E.g. 2. That woman with the 4 inch heels is the Headmaster’s small house.

E.g.3. I am off to the small house.