military vs US Army

military and US Army both are nouns.

Word	Noun	Adjective	Verb	Adverb
military	Yes	Yes	No	No
US Army	Yes	No	No	No

military (noun)	US Army (noun)
the military forces of a nation	the army of the United States of America; the agency that organizes and trains soldiers for land warfare

military (adjective)	US Army (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