in the pre-Reformation church this was the title of the inferior clergy in Latin, rendered sir in English. Many of these minor clergy in the new order found employment as readers and teachers and gradually became known as dominies (cf. "Dominie Sampson" in Scott's Guy Mannering). See also Pope's knight.
Dominus is the Latin word for master or owner. As a title of sovereignty the term under the Roman Republic had all the associations of the Greek Tyrannos; refused during the early principate, it finally became an official title of the Roman Emperors under Diocletian. Dominus, the French equivalent being "sieur", was the Latin title of the feudal, superior and mesne, lords, and also an ecclesiastical and academical title.