armed forces vs headquarters

armed forces and headquarters both are nouns.

Word	Noun	Adjective	Verb	Adverb
armed forces	Yes	No	No	No
headquarters	Yes	No	No	No

armed forces (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