oysters Rockefeller vs oyster

oysters Rockefeller and oyster both are nouns.

Word	Noun	Adjective	Verb	Adverb
oysters Rockefeller	Yes	No	No	No
oyster	Yes	No	Yes	No

As nouns, oyster is a hypernym of oysters Rockefeller; that is, oyster is a word with a broader meaning than oysters Rockefeller:

oysters Rockefeller: oysters spread with butter and spinach and seasonings and baked on the half shell
oyster: edible body of any of numerous oysters

Other hypernyms of oysters Rockefeller include huitre.

oysters Rockefeller (noun)	oyster (noun)
oysters spread with butter and spinach and seasonings and baked on the half shell	marine mollusks having a rough irregular shell; found on the sea bed mostly in coastal waters
	edible body of any of numerous oysters
	a small muscle on each side of the back of a fowl

oysters Rockefeller (verb)	oyster (verb)
	gather oysters, dig oysters