fishnet stockings vs plural form

fishnet stockings and plural form both are nouns.

Word	Noun	Adjective	Verb	Adverb
fishnet stockings	Yes	No	No	No
plural form	Yes	No	No	No

fishnet stockings (noun)	plural form (noun)
leg coverings for women, made from an open mesh fabric resembling netting.	the form of a word that is used to denote more than one