knickerbockers vs plural

knickerbockers and plural both are nouns.

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

knickerbockers (noun)	plural (noun)
(used in the plural) trousers ending above the knee	the form of a word that is used to denote more than one

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