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citadel

American  
[sit-uh-dl, -uh-del] / ˈsɪt ə dl, -əˌdɛl /

noun

citadels plural
  1. a fortress that commands a city and is used in the control of the inhabitants and in defense during attack or siege.

  2. any strongly fortified place; stronghold.

  3. (formerly) a heavily armored structure on a warship, for protecting the engines, magazines, etc.


citadel British  
/ -ˌdɛl, ˈsɪtədəl /

noun

  1. a stronghold within or close to a city

  2. any strongly fortified building or place of safety; refuge

  3. a specially strengthened part of the hull of a warship

  4. (often capital) the headquarters of the Salvation Army

"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

Other Word Forms

Noun Inflected Forms

Etymology

Origin of citadel

1580–90; < Middle French citadelle < Old Italian cittadella, equivalent to cittad ( e ) city + -ella -elle

Explanation

A citadel is a fortified structure designed to provide protection during a battle. So, back in the days when pillaging was commonplace, it was a good idea to know where your nearest citadel was. Among the most historically famous citadels are the Acropolis in Athens and the Tower of London. Even though we're building fewer physical fortresses these days, citadel remains a useful word, particularly when you need to create a metaphor suggesting strength and safety. As poet John Keats wrote, "[I]t appears to me that almost any man may like the spider spin from his own inwards his own airy citadel."

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Vocabulary lists containing citadel

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.

May and June shattered the previous monthly records for individual investors’ trading activity, according to Scott Rubner, head of equity and equity-derivatives strategy at Citadel.

From MarketWatch • Jul. 1, 2026

“Retail cash equity volumes ran 60% above the 2025 average and more than twice the 2024 average in May,” Citadel said.

From Barron's • Jun. 23, 2026

She said she looks forward to using Metro to travel to the Citadel Outlets as well as to her hospital in Pasadena.

From Los Angeles Times • Jun. 19, 2026

Citadel acknowledges that its CEO was Miami’s “mystery” condo buyer, paving the way to develop a new apartment building in the financial district.

From The Wall Street Journal • Jun. 16, 2026

Gandalf dismounted, for no horse was allowed in the Citadel, and Shadowfax suffered himself to be led away at the soft word of his master.

From "The Return of the King" by J.R.R. Tolkien

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