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.

To furnish with fortresses; to guard; to fortify. Shak.