plural vs underpants

plural and underpants both are nouns.

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

plural (noun)	underpants (noun)
the form of a word that is used to denote more than one	an undergarment that covers the body from the waist no further than to the thighs; usually worn next to the skin

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