citadel

UK: /ˈsɪtəd^əl/, /ˈsɪtədɛl/

US: /ˈsɪtədəl, -əˌdɛl/

US: (sit′ə dl, -ə del′)

WordReference Random House Learner's Dictionary of American English © 2026

cit•a•del /ˈsɪtədəl, -əˌdɛl/   n. [countable]

1. a fortress for defending a city.
2. any strongly fortified place;
   stronghold:
   a citadel of right-wing economists.

WordReference Random House Unabridged Dictionary of American English © 2026

cit•a•del  (sit′ə dl, -ə del′), n. 

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

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

Collins Concise English Dictionary © HarperCollins Publishers::

citadel / ˈsɪtəd^əl -ˌdɛl/ noun

1. a stronghold within or close to a city
2. any strongly fortified building or place of safety; refuge

Etymology: 16th Century: from Old French citadelle, from Old Italian cittadella a little city, from cittade city, from Latin cīvitās