Tutor

A tutor was one who privately taught a single student or a very small group.

List of known tutors
Aristotle - tutor to Alexander the Great. (AUDIO: Mask of Tragedy), Bengel - a senior tutor. (AUDIO: White Ghosts), Borusa - tutor to the First Doctor. (TV: The Deadly Assassin), the First Doctor - tutor to Jane Grey. (PROSE: The Nine-Day Queen), the Twelfth Doctor - tutor to Bill Potts at St Luke's University in the 2010s. (TV: The Pilot), Marion Fleming - personal tutor to Alex Campbell in the 2190s. (AUDIO: An Earthly Child), Bernard Helmann - philosophy tutor at the University of Oxford. (PROSE: Come Friendly Bombs...), Magrantine - a Kaled tutor. (AUDIO: Innocence), Sepulchra - tutor to Caleera at the Time Lord Academy. (AUDIO: Scenes From Her Life) and Edward Stott - university principal who acted as tutor to an expedition seeking the Artifact around 2515. (PROSE: Parasite)