military vs headquarters

military and headquarters both are nouns.

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

military (noun)	headquarters (noun)
the military forces of a nation	the military installation from which a commander performs the functions of command
	(usually plural) the office that serves as the administrative center of an enterprise
	(plural) a military unit consisting of a commander and the headquarters staff

military (adjective)	headquarters (adjective)
associated with or performed by members of the armed services as contrasted with civilians
characteristic of or associated with soldiers or the military
of or relating to the study of the principles of warfare