harrier vs hound dog

harrier and hound dog both are nouns.

Word	Noun	Adjective	Verb	Adverb
harrier	Yes	No	No	No
hound dog	Yes	No	No	No

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

harrier: a hound that resembles a foxhound but is smaller; used to hunt rabbits
hound dog: any of several breeds of dog used for hunting typically having large drooping ears

Other hypernyms of harrier include hound.

harrier (noun)	hound dog (noun)
hawks that hunt over meadows and marshes and prey on small terrestrial animals	any of several breeds of dog used for hunting typically having large drooping ears
a hound that resembles a foxhound but is smaller; used to hunt rabbits
a persistent attacker