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]
(..) But my job is done here. Got you two geniuses together. Good luck tomorrow, Otto. Nobel Prize. We'll see you in Sweden! Interesting fellow, your friend. I won't take much of your time. Now I remember you. You're Connors' student. He tells me you're brilliant. He also tells me you're lazy. (..)2004 Spider-Man 2