MP vs military policeman

MP and military policeman both are nouns.

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

As nouns, MP and military policeman are synonyms defined as:

MP and military policeman: a member of the military police who polices soldiers and guards prisoners

MP (noun)	military policeman (noun)
a military corps that enforces discipline and guards prisoners	a member of the military police who polices soldiers and guards prisoners
a member of the military police who polices soldiers and guards prisoners