mullet vs fish

mullet and fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
mullet	Yes	No	No	No
fish	Yes	No	Yes	No

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

mullet (noun)	fish (noun)
bottom dwelling marine warm water fishes with two barbels on the chin	any of various mostly cold-blooded aquatic vertebrates usually having scales and breathing through gills
freshwater or coastal food fishes a spindle-shaped body; found worldwide	the flesh of fish used as food
highly valued lean flesh of marine or freshwater mullet

mullet (verb)	fish (verb)
	catch or try to catch fish or shellfish
	seek indirectly