citadel

noun

cit·​a·​del ˈsi-tə-dᵊl 

-ˌdel

1

: a fortress that commands (see command entry 1 sense 2c) a city

2

: stronghold

the nation's citadel of health research

—Constance Holden

a citadel of higher education

Synonyms

• fortress
• stronghold
• bastion
• fortification
• castle
• fort

Examples of citadel in a Sentence

We visited a medieval citadel in Italy.

a massive stone citadel continues to command the city of Halifax, Nova Scotia

Recent Examples on the Web

Peru’s most famous archaeological site is Machu Picchu, the ancient Inca citadel built in the Andes Mountains in the 15th century. —Ellen Wexler, Smithsonian Magazine, 2 July 2025

Castillo San Felipe del Morro, Puerto Rico Guarding the entrance to San Juan Bay, this 16th-century Spanish citadel is one of the most impressive structures in the Caribbean. —Cnn.com Wire Service, Mercury News, 10 June 2025

Originally built as a Byzantine citadel, it was reworked into its present Gothic form by the crusading Knights of St John when Rhodes served as the headquarters of their grand master. —Cnn.com Wire Service, Mercury News, 10 June 2025

Prague Castle, Czech Republic Prague’s imposing citadel is also one of the few castles anywhere in the world that still boasts real political power — the official residence of the president of the Czech Republic. —Cnn.com Wire Service, Mercury News, 10 June 2025

Word History

Etymology

Middle French citadelle, from Old Italian cittadella, diminutive of cittade city, from Medieval Latin civitat-, civitas — more at city

First Known Use

1542, in the meaning defined at sense 1

Rhymes for citadel

• bagatelle
• caravel
• carousel
• carrousel
• clientele
• commonweal
• decibel
• demoiselle
• fontanelle
• infidel
• isabel
• machiavel

Kids Definition

citadel

noun

cit·​a·​del ˈsit-əd-ᵊl 

-ə-ˌdel

1

: a fortress that sits high above a city

2

: a strong fortress