half-bastion vs bastion

half-bastion and bastion both are nouns.

Word	Noun	Adjective	Verb	Adverb
half-bastion	Yes	No	No	No
bastion	Yes	No	No	No

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

half-bastion: in military architecture, a bastion constructed of one face, and one flank.
bastion: projecting part of a rampart or other fortification

half-bastion (noun)	bastion (noun)
in military architecture, a bastion constructed of one face, and one flank.	projecting part of a rampart or other fortification
	a stronghold into which people could go for shelter during a battle
	a group that defends a principle