A mansion that is (or formerly was) occupied by an aristocratic family(noun)
WordNet. Princeton University. 2010.
Use "stately home" in a sentence
"The persecution which drove the community from its stately home at Muri seems in no way to have lessened the numbers and good works of the monks; indeed there has been a notable increase in the personnel of the convent in recent years and fresh demands are ever being made on their manifold activities."