fortress

noun

for·​tress ˈfȯr-trəs 

: a fortified place : stronghold

especially : a large and permanent fortification sometimes including a town

fortresslike

ˈfȯr-trəs-līk 

adjective

Synonyms of fortress

• stronghold
• citadel
• fortification
• castle
• bastion
• fort

Examples of fortress in a Sentence

the boys built a snow fortress and then challenged the neighborhood kids to an in-your-face snowball fight

Recent Examples on the Web

For this heinous crime, Brennick receives a punishing sentence at the futuristic, high-tech fortress prison run by the nefarious Men-Tel Corporation. —Sergio Pereira, Space.com, 25 Apr. 2026

Over the years, the former bank data processing center near Hartford’s minor league ballpark deservedly earned the moniker of bunker-like fortress — but never more so than now when the city wants to tear it down for redevelopment. —Kenneth R. Gosselin, Hartford Courant, 24 Apr. 2026

Alcatraz began as a military fortress and lighthouse, then became a military prison, converted to civilian use in 1933. —Sun Sentinel Editorial Board, Sun Sentinel, 24 Apr. 2026

Completed in 1960, its diagrid exterior, clad in Portland stone, sought to blend in with the rest of the upscale Mayfair neighborhood while asserting itself as an impenetrable fortress. —Rebecca Rose, Travel + Leisure, 24 Apr. 2026

Word History

Etymology

Middle English forteresse, from Anglo-French fortelesce, forteresse, from Medieval Latin fortalitia, from Latin fortis strong

First Known Use

14th century, in the meaning defined above

Kids Definition

fortress

noun

for·​tress ˈfȯr-trəs 

: a fortified place