Catholic Encyclopedia (1913)/Monseigneur
(From mon, "my" and seigneur, ("elder" or "lord," like Lat. senior)
A French honorific appellation, etymologically corresponding to the English "my lord," and the Italian monsignore. It is, after all, nothing but the French monsieur; but, while the latter has become current as applied to every man who is in good society, Monseigneur has retained its honorific force. In ecclesiastical usage it is reserved for bishops and archbishops, and is chiefly employed when speaking or writing to them. It is used before the name (thus abridged: Msgr. Dupanloup). Formerly it was not prefixed to the title of dignity, but it is now, as "Mgr l'évêque N. . . ." The term Monseigneur is also used as the equivalent of the Italian Monsignore, and as the latter title is given to Roman prelates, some confusion results; in Italy, however, no inconvenience arises from this usage as in that country bishops have the title of Eccellenza, i.e., Excellency. In France, only the Archbishop of Reims, as legatus natus, has the title of Excellency (See ).
HERICOURT, Les lois ecclesiastiques de France, E.V., 22.