Fortress

n. [Fr. forteresse, Pr. forteressa, fortalessa, forteza, It. fortezza, from Lat. fortis, strong, Fr. & Pr. fort, It. & Pg. forte, Sp. fuerte. See FORTALICE and FORT.] A fortified place; a fort; a castle; a stronghold; a place of defense or security; usually, a city or town well fortified.

Synonyms—FORTRESS, FORTIFICATION, CASTLE, CITADEL. A fortress is constructed for military purposes only, and is permanently garrisoned; a fortification is built to defend harbors, cities, &c.; a castle is a fortress of early times which was ordinarily a palatial dwelling; a citadel is the stronghold of a fortress or city, &c.

The castle of Macduff I will surprise. Shak.

I'll to my charge, the citadel, repair. Dryden.

God is our fortress, in whose conquering name Let us resolve to scale their flinty bulwarks. Shak.