The definition of a citadel is a place where people go for safety or to defend.(noun)
A medieval castle is an example of a citadel.
See citadel in Webster's New World College Dictionary
Origin: < It cittadella, dim. of cittade, city < L civitas, citizenship: see city
See citadel in American Heritage Dictionary 4
Origin: French citadelle
Origin: , from Italian cittadella
Origin: , diminutive of città, city
Origin: , from Latin cīvitās; see city.
Learn more about citadel