underdrawers vs plural

underdrawers and plural both are nouns.

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

underdrawers (noun)	plural (noun)
underpants worn by men	the form of a word that is used to denote more than one

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