monsieur Meaning, Definition & Usage

  1. noun used as a French courtesy title; equivalent to English `Mr'

WordNet

Mon*sieur" noun
Etymology
F., fr. mon my + Sieur, abbrev. of seigneur lord. See Monseigneur.
Wordforms
plural Messieurs
Definitions
  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.

Webster 1913