docent

adj

1. Instructive; that teaches.

noun

1. A teacher or lecturer at some universities (in central Europe, etc.)

   “Zermelo had been a docent at Göttingen when Kit was there and, like Russell, had been preoccupied with the set of all sets that are not members of themselves.”

2. (US)A tour guide at a museum, art gallery, historical site, etc.

   “The docent greeted the visitors and welcomed them to the Smithsonian.”

   “She was listening distractedly as an elderly docent intoned to a circle of listless children.”