cowfish vs boxfish

cowfish and boxfish both are nouns.

Word	Noun	Adjective	Verb	Adverb
cowfish	Yes	No	No	No
boxfish	Yes	No	No	No

As nouns, boxfish is a hypernym of cowfish; that is, boxfish is a word with a broader meaning than cowfish:

cowfish: trunkfish having hornlike spines over the eyes
boxfish: any of numerous small tropical fishes having body and head encased in bony plates

Other hypernyms of cowfish include trunkfish.

cowfish (noun)	boxfish (noun)
trunkfish having hornlike spines over the eyes	any of numerous small tropical fishes having body and head encased in bony plates