A fortified place; a large and permanent fortification, sometimes including a town; for example a fort, a castle; a stronghold; a place of defense or security.

(transitive) To furnish with a fortress or with fortresses; to guard, to fortify.

plural of fortress / plural of fortresse

simple past tense and past participle of fortress

present participle of fortress

Obsolete spelling of fortress

(informal) The US WWII heavy bomber Boeing B-17.

(historical) The areas of continental Europe occupied by Nazi Germany during the Second World War, as opposed to the United Kingdom across the Channel.

Resembling a fortress in shape or impregnability.