military vs military policeman

military and military policeman both are nouns.

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

military (noun)	military policeman (noun)
the military forces of a nation	a member of the military police who polices soldiers and guards prisoners

military (adjective)	military policeman (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