plural vs public works

plural and public works both are nouns.

Word	Noun	Adjective	Verb	Adverb
plural	Yes	Yes	No	No
public works	Yes	No	No	No

plural (noun)	public works (noun)
the form of a word that is used to denote more than one	structures (such as highways or schools or bridges or docks) constructed at government expense for public use

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