pike perch vs walleye

pike perch and walleye both are nouns.

Word	Noun	Adjective	Verb	Adverb
pike perch	Yes	No	No	No
walleye	Yes	No	No	No

As nouns, walleye is a hyponym of pike perch; that is, walleye is a word with a more specific, narrower meaning than pike perch:

Other hyponyms of pike perch include dory, jack salmon, Stizostedion vitreum, walleyed pike.

pike perch (noun)	walleye (noun)
any of several pike-like fishes of the perch family	pike-like freshwater perches
	strabismus in which one or both eyes are directed outward