Rock Cornish vs poultry

Rock Cornish and poultry both are nouns.

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

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

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

Other hypernyms of Rock Cornish include domestic fowl, fowl.

Rock Cornish (noun)	poultry (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
	flesh of chickens or turkeys or ducks or geese raised for food