Fish vs worker

Fish and worker both are nouns.

Word	Noun	Adjective	Verb	Adverb
Fish	Yes	No	No	No
worker	Yes	No	No	No

As nouns, worker is a hypernym of Fish; that is, worker is a word with a broader meaning than Fish:

Other hypernyms of Fish include actor, doer.

Fish (noun)	worker (noun)
the twelfth sign of the zodiac; the sun is in this sign from about February 19 to March 20	sterile member of a colony of social insects that forages for food and cares for the larvae
(astrology) a person who is born while the sun is in Pisces	a person who works at a specific occupation
	a member of the working class (not necessarily employed)
	a person who acts and gets things done