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]
(..) Wait, wait, wait ! Go, go ! Down, down ! Bye ! Sorry ! Pretty tough for a valet, this fellow. - Seems more like a cop. - l think he was. (Jack) Oh, shit ! No, over here ! Quick ! (..)1997 Titanic