1. Citadel (noun): A fortress protecting a city or region, typically located on high ground. 2. Citadel (noun): A stronghold or central area of a place, symbolizing strength or dominance. 3. Citadel (noun): A metaphorical term for a place of refuge or protection. The term "citadel" refers to a fortress or stronghold, often built in […] The post Citadel: Definition, Meaning, and Examples appeared first on US Dictionary.