in the plural Messeigneurs, a title of honour and respect used by the French in writing to persons of superior rank or quality, before the late abolition of all ranks.
Dukes, peers, archbishops, bishops, and presidents à la mortier, were complimented with the title of Monsieur. In the petitions presented to the sovereign courts, they used the term Messeigneurs.
Monsieur, absolutely used, was a title restricted to the dauphin of France. This custom was unknown till the time of Louis XIV. before which the dauphin was styled Monsieur le Dauphin.
in the plural Messeigneurs, a term or title of civility, used by the French in speaking to their equals, or those a little below them, answering to Mr or Sir among the English.
Monsieur, absolutely used, was a title or quality appropriated to the second son of France, or the king's brother. The king was also called Monsieur, but that only by the children of France.