Magister

The title and rank of Magister is granted to all those Adeptus Magica who have furthered the magical arts, who have taken on to teach either at a registered academy or have registered students of their own with the Arcane Guilds or The Guilds of Magic.
The former for specialized training, the latter for general training.

As a result, the title of Magister will also be conveyed to an Adeptus Minor who has finished his education within his specific field to the equivalent of a mundane guild's title of Master.
So a furrier-mage who trains others will receive the rank and title of Magister furrier-mage.

In recent years it has become more and more widespread to address such an Adeptus Minor as Master respectively Mistress, emphasizing the advanced level of knowledge the craft the individual shows much stronger than the task of training she may have taken on. The address has as such become something along with Master Healer-mage etc.