Bible Encyclopedias
Sir

Cyclopedia of Biblical, Theological and Ecclesiastical Literature

(as the English of dominus) was the title adopted by priests, as "dom" by monks, and in consequence they were commonly called Sir Johns. There were three sirs — sir king, sir priest, and sir knight. At the Reformation it was the title of those in orders, but not graduated — those who had graduated being known as magisters (masters).