peep sight vs gunsight

peep sight and gunsight both are nouns.

Word	Noun	Adjective	Verb	Adverb
peep sight	Yes	No	No	No
gunsight	Yes	No	No	No

As nouns, gunsight is a hypernym of peep sight; that is, gunsight is a word with a broader meaning than peep sight:

peep sight: rear gunsight having an adjustable eyepiece with a small aperture through which the front sight and the target are aligned
gunsight: a sight used for aiming a gun

Other hypernyms of peep sight include gun-sight.

peep sight (noun)	gunsight (noun)
rear gunsight having an adjustable eyepiece with a small aperture through which the front sight and the target are aligned	a sight used for aiming a gun