motorcycle cop vs motorcycle policeman

motorcycle cop and motorcycle policeman both are nouns.

Word	Noun	Adjective	Verb	Adverb
motorcycle cop	Yes	No	No	No
motorcycle policeman	Yes	No	No	No

As nouns, motorcycle cop and motorcycle policeman are synonyms defined as:

motorcycle cop and motorcycle policeman: a policeman who rides a motorcycle (and who checks the speeds of motorists)

Other synonyms of motorcycle cop include speed cop.

motorcycle cop (noun)	motorcycle policeman (noun)
a policeman who rides a motorcycle (and who checks the speeds of motorists)	a policeman who rides a motorcycle (and who checks the speeds of motorists)