a teaching/research 'fellow' [=a graduate student who gets money in exchange for teaching/research]
He attended the concert with a 'fellow' student. [=someone who is a student, as he is]
He has always tried to be of service to 'his fellow man'. [=to other people]
(..) We escaped. The Brotherhood took us prisoner. They sold me to the innkeep. Big ugly fellow. Foul mouth and a face like a half-burnt ham. - The Hound. That's the one. (..)2014 TvShow: Game of Thrones Title: Mockingbird Season: 4 Episode 7