frost fish vs percoid

frost fish and percoid both are nouns.

Word	Noun	Adjective	Verb	Adverb
frost fish	Yes	No	No	No
percoid	Yes	No	No	No

As nouns, percoid is a hypernym of frost fish; that is, percoid is a word with a broader meaning than frost fish:

frost fish: long-bodied marine fishes having a long whiplike scaleless body and sharp teeth; closely related to snake mackerel
percoid: any of numerous spiny-finned fishes of the order Perciformes

Other hypernyms of frost fish include percoid fish, percoidean.

frost fish (noun)	percoid (noun)
long-bodied marine fishes having a long whiplike scaleless body and sharp teeth; closely related to snake mackerel	any of numerous spiny-finned fishes of the order Perciformes