fish vs look for

fish is a noun but look for is not a noun.

Word	Noun	Adjective	Verb	Adverb
fish	Yes	No	Yes	No
look for	No	No	Yes	No

As verbs, look for is a hypernym of fish; that is, look for is a word with a broader meaning than fish:

Other hypernyms of fish include search, seek.

fish (noun)	look for (noun)
any of various mostly cold-blooded aquatic vertebrates usually having scales and breathing through gills
the flesh of fish used as food

fish (verb)	look for (verb)
catch or try to catch fish or shellfish	try to locate or discover, or try to establish the existence of
seek indirectly	be excited or anxious about