Professor

A professor was a teacher at a university or at an institute.

Doctor Leah Brahms was a Professor of Theoretical Physics at the Daystrom Institute of Technology, Mars, prior to stardate 43205. 

Professor was an instructor at Starfleet Academy. One of his students was B'Elanna Torres. 

Miles O'Brien became a Professor of Engineering at Starfleet Academy after the end of the Dominion War. 

Tuvok was once a professor of archery at the Vulcan Institute for Defensive Arts.