setter vs gun dog

setter and gun dog both are nouns.

Word	Noun	Adjective	Verb	Adverb
setter	Yes	No	No	No
gun dog	Yes	No	No	No

As nouns, gun dog is a hypernym of setter; that is, gun dog is a word with a broader meaning than setter:

setter: a long-haired dog formerly trained to crouch on finding game but now to point
gun dog: a dog trained to work with sportsmen when they hunt with guns

Other hypernyms of setter include sporting dog.

setter (noun)	gun dog (noun)
a long-haired dog formerly trained to crouch on finding game but now to point	a dog trained to work with sportsmen when they hunt with guns
one who sets written material into type