- milliroentgen; milliroentgens.
- mister: a title of respect prefixed to a man's name or position: Mr. Lawson; Mr. President.
- a title prefixed to a mock surname that is used to represent possession of a particular attribute, identity, etc., especially in an idealized or excessive way: Mr. Democrat; Mr. Perfect; Mr. Macho.
- a title used before a man's name or names or before some office that he holds
- (in military contexts) a title used in addressing a warrant officer, officer cadet, or junior naval officer
- a title placed before the surname of a surgeon
- Master of the Rolls
- motivation(al) research
