plural form vs dark glasses

plural form and dark glasses both are nouns.

Word	Noun	Adjective	Verb	Adverb
plural form	Yes	No	No	No
dark glasses	Yes	No	No	No

plural form (noun)	dark glasses (noun)
the form of a word that is used to denote more than one	(plural) spectacles that are darkened or polarized to protect the eyes from the glare of the sun