plural vs Jockey shorts

plural and Jockey shorts both are nouns.

Word	Noun	Adjective	Verb	Adverb
plural	Yes	Yes	No	No
Jockey shorts	Yes	No	No	No

plural (noun)	Jockey shorts (noun)
the form of a word that is used to denote more than one	(used in the plural) short tight-fitting underpants (trade name Jockey shorts)

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