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]
(..) did they get out? No, they were blown. The story is you blew them to save your own skin. 'After the interrogators had cleared out, this little fellow turned up. 'Looked like a priest. 'That's when they really started on me.' What was your last line of defence, hm? The mole. Control's crazy theory. (..)2011 Tinker Tailor Soldier Spy
(..) Come on, lads. Keep up. Come on, Bill! - Got your specs on, Jumbo? - Yes, sir. Come here. Who's that fellow down there? I don't know, sir. Who is he? Beggar man? Thief? Why doesn't he look this way, hm? (..)2011 Tinker Tailor Soldier Spy