cowbarn vs barn

cowbarn and barn both are nouns.

Word	Noun	Adjective	Verb	Adverb
cowbarn	Yes	No	No	No
barn	Yes	No	No	No

As nouns, barn is a hypernym of cowbarn; that is, barn is a word with a broader meaning than cowbarn:

cowbarn: a barn for cows
barn: an outlying farm building for storing grain or animal feed and housing farm animals

cowbarn (noun)	barn (noun)
a barn for cows	an outlying farm building for storing grain or animal feed and housing farm animals
	(physics) a unit of nuclear cross section; the effective circular area that one particle presents to another as a target for an encounter