1. [ noun ] (military) a group that defends a principle

"a bastion against corruption" "the last bastion of communism"

Related terms: defense
2. [ noun ] a stronghold into which people could go for shelter during a battle
Synonyms: citadel
Related terms: stronghold kremlin kremlin Alhambra acropolis
3. [ noun ] (military) projecting part of a rampart or other fortification
Related terms: fortification
Similar spelling:   bastioned