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]
(..) I will take the corpse... The patient... Look, an elephant! Do not shoot! He will drop Leo! Do not shoot! Oh, shit! That is a no-fly zone, fellow. Danny! He is ticking! Move the crane as fast as you can! Danny, stop the crane now! Drop! Go, go, go! Drop, you gas bag! Everybody out of here! (..)1993 Last Action Hero