dominus

plural domini

1. historicalmaster; sir; a title of respect formerly applied to a knight or clergyman, and sometimes to the lord of a manor, castle or an academic master

   The vesper bell had rung its parting note; the domini were mostly caged in comfortable quarters, discussing the merits of old port; and the merry student had closed his oak, to consecrate the night to friendship, sack, and claret.

   January 1848, The New Sporting Magazine, volume 15, page 23