military vs military group

military and military group both are nouns.

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

military (noun)	military group (noun)
the military forces of a nation	a unit that is part of some military service

military (adjective)	military group (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