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]
(..) someone taken care of. - Who's the guy? - Well, he's not a guy, per se. Um... He's an ogre. Hey, buddy, let me clue you in. There's only one fellow who can handle a job like that, and, frankly... he don't like to be disturbed. Where could I find him? Hello? Who dares enter my room? (..)2004 Shrek 2