bow-wow vs domestic dog

bow-wow and domestic dog both are nouns.

Word	Noun	Adjective	Verb	Adverb
bow-wow	Yes	No	No	No
domestic dog	Yes	No	No	No

As nouns, domestic dog is a hypernym of bow-wow; that is, domestic dog is a word with a broader meaning than bow-wow:

bow-wow: informal terms for dogs
domestic dog: a member of the genus Canis (probably descended from the common wolf) that has been domesticated by man since prehistoric times; occurs in many breeds

Other hypernyms of bow-wow include Canis familiaris, dog.

bow-wow (noun)	domestic dog (noun)
informal terms for dogs	a member of the genus Canis (probably descended from the common wolf) that has been domesticated by man since prehistoric times; occurs in many breeds
the bark of a dog