24
stronghold(noun, support, hold, cover, keep)
17
citadel(noun, stronghold, keep, support, defense)
14
fort(noun, hold, cover, keep, position)
13
castle(noun, keep, defense, refuge, fortification)
9
fastness(noun, hold, cover, keep, position)
9
bastion(noun, support, place, cover, position)
9
haven
8
garrison(noun, cover, position, guard, shield)
8
base complex(significance, facility, army)
7
defense(noun, support, cover, guard, resistance)
6
fortification(noun, support, hold, cover, keep)
6
bulwark(noun, support, cover, position, guard)
6
redoubt(noun, support, cover, position, top)
6
tower(noun, hold, part, keep, top)
6
barrier(noun, support, defense, fortification, stronghold)
6
keep(noun, hold, defense, refuge, stronghold)
5
donjon(noun, hold, keep, defense, stronghold)
5
dungeon(defense, prison)
5
hold(noun, keep, defense, stronghold, prison)
5
rampart(noun, support, cover, position, guard)
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APASmart Define. (2015). fortress thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/fortress/thesaurus/synonyms
ChicagoSmart Define. 2015. "fortress thesaurus" https://smartdefine.org/fortress/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2015, fortress thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/fortress/thesaurus/synonyms>.
MLASmart Define. "fortress thesaurus" 15 May 2015. Web. 20 September 2026. <https://smartdefine.org/fortress/thesaurus/synonyms>