Jockey shorts vs plural form

Jockey shorts and plural form both are nouns.

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

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