military headquarters vs plural

military headquarters and plural both are nouns.

Word	Noun	Adjective	Verb	Adverb
military headquarters	Yes	No	No	No
plural	Yes	Yes	No	No

military headquarters (noun)	plural (noun)
the military installation from which a commander performs the functions of command	the form of a word that is used to denote more than one

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