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Synonyms

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.

fortress British  
/ ˈfɔːtrɪs /

noun

  1. a large fort or fortified town

  2. a place or source of refuge or support

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

verb

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Dominating a sandy stretch of Qatar’s northern coast, Ras Laffan is a sprawling industrial fortress of pipes, flare stacks and loading berths built around the world’s largest artificial harbor.

From The Wall Street Journal • Mar. 19, 2026

Masala, the analyst, said that Narva today resembled a "fortress."

From Barron's • Feb. 6, 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

Lazlo they regarded with curiosity, and the rest of the strangers as well, once their camels had been brought through the gates into the central plaza of the fortress.

From "Strange the Dreamer" by Laini Taylor

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.