D defs.my
Entry 1 sense Webster, 1913

Monseigneur

/(F. môN`sā̇`nyẽr"; E. mŏn*sĕn"yẽr)/ · Mon·sei·gneur · IPA /mɒnˈsinjəɹ/
01 n. My lord; -- a title in France of a person of high birth or rank; as, Monseigneur the Prince, or Monseigneur the Archibishop. It was given,…
pl. Messeigneurs ((F. mā̇`sā̇`nyẽr"; E. mĕs*sĕn"yẽrz))
  1. 1.
    My lord; -- a title in France of a person of high birth or rank; as, Monseigneur the Prince, or Monseigneur the Archibishop. It was given, specifically, to the dauphin, before the Revolution of 1789. (Abbrev. Mgr.)