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

• 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

Since its launch, the CUDA ecosystem has created an impenetrable fortress of developer lock-in that competitors have failed to breach despite years of effort. —Steven Wolfe Pereira, Forbes.com, 9 July 2025

City Hall, Albany—these have been fortresses of political entrenchment for a century. —Benjamin Wallace-Wells, New Yorker, 25 June 2025

Iran's most advanced and hardened nuclear facility, the Fordow plant in the country's northwest, is a fortress. —Adeola Adeosun, MSNBC Newsweek, 21 June 2025

The then-British fortress was famously captured by Ethan Allen and Benedict Arnold in May 1775, marking a pivotal moment in the early stages of the Revolutionary War. —Andrea Margolis, FOXNews.com, 17 June 2025

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