Rock Cornish vs fowl

Rock Cornish and fowl both are nouns.

Word	Noun	Adjective	Verb	Adverb
Rock Cornish	Yes	No	No	No
fowl	Yes	No	Yes	No

As nouns, fowl is a hypernym of Rock Cornish; that is, fowl is a word with a broader meaning than Rock Cornish:

Rock Cornish: small plump hybrid developed by crossbreeding Plymouth Rock and Cornish fowl
fowl: a domesticated gallinaceous bird thought to be descended from the red jungle fowl

Other hypernyms of Rock Cornish include domestic fowl, poultry.

Rock Cornish (noun)	fowl (noun)
small plump hybrid developed by crossbreeding Plymouth Rock and Cornish fowl	a domesticated gallinaceous bird thought to be descended from the red jungle fowl
	the flesh of a bird or fowl (wild or domestic) used as food

Rock Cornish (verb)	fowl (verb)
	hunt fowl in the forest
	hunt fowl