alligatorfish vs poacher

alligatorfish and poacher both are nouns.

Word	Noun	Adjective	Verb	Adverb
alligatorfish	Yes	No	No	No
poacher	Yes	No	No	No

As nouns, poacher is a hypernym of alligatorfish; that is, poacher is a word with a broader meaning than alligatorfish:

alligatorfish: small very elongate sea poachers
poacher: small slender fish (to 8 inches) with body covered by bony plates; chiefly of deeper northern Pacific waters

Other hypernyms of alligatorfish include sea poacher, sea poker.

alligatorfish (noun)	poacher (noun)
small very elongate sea poachers	small slender fish (to 8 inches) with body covered by bony plates; chiefly of deeper northern Pacific waters
	a cooking vessel designed to poach food (such as fish or eggs)
	someone who hunts or fishes illegally on the property of another