Chateau
Chateau , noun
[French château a castle. See Castle.]
1.
A castle or a fortress in France.
2.
A manor house or residence of the lord of the manor; a gentleman's country seat; also, particularly, a royal residence; as, the chateau of the Louvre; the chateau of the Luxembourg.
The distinctive, French term for a fortified castle of the middle ages is château-fort.