Magister

"Magister" was, according to the Third Doctor, "the Latin word for Master". used the word as an alias to insinuate himself socially into the Devil's End community as a vicar, under the name "Victor Magister". Upon hearing the name, the Doctor immediately realised his nemesis' involvement. Olive Hawthorne instead recognised the name as being given to "the leader of a black magic coven". Jo Grant, on the other hand, had never heard the word in her life. (TV: The Dæmons)

during the Time War again used the Magister alias while posing as a village priest in the 1940s, as "Reverent Magister". (AUDIO: The Survivor) Later still, called herself "Miss Magister" while working as a schoolteacher at a boarding school. (PROSE: Yes, Missy)

In one universe, the Doctor's oldest friend was named the Magistrate. (PROSE: The Infinity Doctors)