- castle
- citadel
- fort
- fortress
- refuge
- shelter
Synonyms for castellum
- ara – altar, protection, refuge
- arcis – citadel, donjon, fortress, keep, stronghold
- arx – citadel, donjon, fortress, keep, stronghold, town
- castrum – castle, fort, fortified encampment, fortress, station
- defendo – protect, shelter, to defend, to support, ward off
- moenia – castle, city, dwelling, fortifications of a city, fortress, mansion, ramparts, walled town, walls
- pugnaculum – fortress
- refugium – refuge
- tectum – bury, conceal, hide, protect, shelter, shield, to cover