castle

1 a structure or place from which one can resist attack the implacable attackers placed the castle under a prolonged siege Synonyms bastion, fort, citadel, fastness, fortification, fortress, hold, redoubt, strongholdRelated Words battlement, breastwork, bulwark, earthwork, embattlement, parapet, rampart; bunker, dugout; blockhouse, garrison house; alcazar, casbah (also kasbah)

2 a large impressive residence the mining tycoon built a magnificent castle on the hill overlooking the town Synonyms mansion, château, estate, hacienda, hall, manor, manor house, manse, palace, villaRelated Words showplace; abode, domicile, dwelling, habitation, hearth, home, house, lodging(s), pad, place; housing, nest, quarter(s), residency, roof; great house; country house, countryseat; aerie, penthouse; salon, suite, town house