MONSIEUR (Fr., formed from man, my, and sieur, lord), the general title of address in France used vocatively in speaking formally to any male person, like the English " sir " or prefixed to the name like the English " Mr." It is, however, in France also prefixed to nobiliary, official, and other titles, e.g. Monsieur le president, Monsieur le due d'E., etc. It is abbreviated M., not Mons. As a specific title " Monsieur " (tout court) was used from the time of Louis XIV. of the eldest brother of the king, as " Monseigneur " was of the dauphin; as a general title of address it was given to the princely members of a royal house.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)