\Mon*sieur"\, n.; pl. {Messieurs}. [F., fr. mon my +
Sieur, abbrev. of seigneur lord. See {Monseigneur}.]
1. The common title of civility in France in speaking to, or
   of, a man; Mr. or Sir. [Represented by the abbreviation M.
   or Mons. in the singular, and by {MM.} or {Messrs.} in the
   plural.]
2. The oldest brother of the king of France.
3. A Frenchman. [Contemptuous] --Shak.