What is Monsignor?
1.
a form of address -- and by extension a title/rank(etymology < monsignore, italian <meum signorem , low latin, literally "my lord") -- for certain prelates(higher-levelpriests) of the
After serving many years as vicar-general for the Archdiocese, Fr. O'Donohue was created a Protonotary-Apostolic with the title of "Monsignor."
See