bastion vs defence force

bastion and defence force both are nouns.

Word	Noun	Adjective	Verb	Adverb
bastion	Yes	No	No	No
defence force	Yes	No	No	No

As nouns, defence force is a hypernym of bastion; that is, defence force is a word with a broader meaning than bastion:

bastion: a group that defends a principle
defence force: an organization of defenders that provides resistance against attack

Other hypernyms of bastion include defence, defense, defense force.

bastion (noun)	defence force (noun)
projecting part of a rampart or other fortification	an organization of defenders that provides resistance against attack
a stronghold into which people could go for shelter during a battle
a group that defends a principle