caudal fin vs fish

caudal fin and fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
caudal fin	Yes	No	No	No
fish	Yes	No	Yes	No

caudal fin (noun)	fish (noun)
the tail of fishes and some other aquatic vertebrates	any of various mostly cold-blooded aquatic vertebrates usually having scales and breathing through gills
	the flesh of fish used as food

caudal fin (verb)	fish (verb)
	catch or try to catch fish or shellfish
	seek indirectly