armed forces vs unarmed

armed forces is a noun but unarmed is not a noun.

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

armed forces (noun)	unarmed (noun)
the military forces of a nation

armed forces (adjective)	unarmed (adjective)
	(used of persons or the military) not having or using arms
	(used of plants or animals) lacking barbs or stings or thorns