fortress

American  

[fawr-tris] / ˈfɔr trɪs /

noun

1. a large fortified place; a fort or group of forts, often including a town; citadel.

2. any place of exceptional security; stronghold.

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fortress British  

/ ˈfɔːtrɪs /

noun

1. a large fort or fortified town

2. a place or source of refuge or support

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verb

1. (tr) to protect with or as if with a fortress

Etymology

Origin of fortress

1300–50; Middle English forteresse < Old French < Vulgar Latin *fortaricia (compare Medieval Latin fortalitia ), equivalent to Latin fort ( is ) strong + -ar-, formative of uncertain meaning +- icia -ice

Explanation

A fortress is a large building or complex of buildings used as a military stronghold. In a military sense, a fortress is often called a “fort." From its original sense of stronghold, the word fortress has stretched to include strongholds in a more figurative sense. Martin Luther used fortress to describe unfailing spiritual support when he wrote, “A mighty fortress is our God.” When someone has a hard time trusting others, you might say they have retreated to a "fortress of their own making."

Example Sentences

The island fortress entered American cultural lore after a 1962 escape by three inmates, which became an inspiration for the film "Escape from Alcatraz" starring Clint Eastwood.

From Barron's • Apr. 3, 2026

On Tuesday night, at the fortress of soccer giant Inter Milan, the Norwegians pulled off their most surprising victory yet.

From The Wall Street Journal • Feb. 25, 2026

“The building is a fortress, it’s got thick concrete walls,” he said.

From Los Angeles Times • Jan. 16, 2026

The Maduros tried to escape into a safe place, the US president explained, describing it as a military "fortress".

From BBC • Jan. 4, 2026

The weapons packs they carried out of the fortress were not, in fact, weapons packs.

From "Klawde: Evil Alien Warlord Cat" by Johnny Marciano and Emily Chenoweth

Related Words

• barrier
• citadel
• garrison
• rampart