coffee grounds vs plural

coffee grounds and plural both are nouns.

Word	Noun	Adjective	Verb	Adverb
coffee grounds	Yes	No	No	No
plural	Yes	Yes	No	No

coffee grounds (noun)	plural (noun)
the dregs remaining after brewing coffee	the form of a word that is used to denote more than one

coffee grounds (adjective)	plural (adjective)
	grammatical number category referring to two or more items or units
	composed of more than one member, set, or kind