Mon*sieur" (?), n.; pl. Messieurs (#). [F., fr. mon my + Sieur, abbrev. of seigneur lord. See Monseigneur.]
The common title of civility in France in speaking to, or of, a man; Mr. or Sir.
[Represented by the abbreviation M.
in the singular, and by MM.] or Messrs. in the plural.]
The oldest brother of the king of France.
A Frenchman. [Contemptuous]
© Webster 1913.