tripletail vs percoid

tripletail and percoid both are nouns.

Word	Noun	Adjective	Verb	Adverb
tripletail	Yes	No	No	No
percoid	Yes	No	No	No

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

tripletail: large food fish of warm waters worldwide having long anal and dorsal fins that with a caudal fin suggest a three-lobed tail
percoid: any of numerous spiny-finned fishes of the order Perciformes

Other hypernyms of tripletail include percoid fish, percoidean.

tripletail (noun)	percoid (noun)
large food fish of warm waters worldwide having long anal and dorsal fins that with a caudal fin suggest a three-lobed tail	any of numerous spiny-finned fishes of the order Perciformes