grocery store vs grocery

grocery store and grocery both are nouns.

Word	Noun	Adjective	Verb	Adverb
grocery store	Yes	No	No	No
grocery	Yes	No	No	No

As nouns, grocery store and grocery are synonyms defined as:

Other synonyms of grocery store include food market, market.

grocery store (noun)	grocery (noun)
a marketplace where groceries are sold	a marketplace where groceries are sold
	(usually plural) consumer goods sold by a grocer