stairs vs plural

stairs and plural both are nouns.

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

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

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