plural citadels
: a castle or fort that in past times was used to protect the people of a city if the city was attacked
We visited a medieval citadel in Italy.
—often used figurativelyThe magazine has become a citadel [=stronghold] of liberalism/conservatism.
the citadels of power
Note: In the U.S., The Citadel is the name of a well-known military college.
Cite this Entry
“Citadel.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/citadel. Accessed 21 Jun. 2026.
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