worm fish vs percoid

worm fish and percoid both are nouns.

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

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

worm fish: poorly known family of small tropical shallow-water fishes related to gobies
percoid: any of numerous spiny-finned fishes of the order Perciformes

Other hypernyms of worm fish include percoid fish, percoidean.

worm fish (noun)	percoid (noun)
poorly known family of small tropical shallow-water fishes related to gobies	any of numerous spiny-finned fishes of the order Perciformes