1. A branch of an armed-military force assigned to perform law enforcement duties: An MP is an equivalent to a civilian police officer; however, only MPs, or Military Police, are authorized to serve on military installations while civilian police are not.

An MP also indicates "mounted police" who ride horses when performing special duties as civilian police.

2. A member of a government group in such countries as Great Britain, Canada, etc.: The MP is a Member of Parliament which is the highest legislature in the UK consisting of the sovereign, the House of Lords, and the House of Commons.