plural vs stairs

plural and stairs both are nouns.

Word	Noun	Adjective	Verb	Adverb
plural	Yes	Yes	No	No
stairs	Yes	No	No	No

plural (noun)	stairs (noun)
the form of a word that is used to denote more than one	a flight of stairs or a flight of steps

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