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]
(..) sitting ♪ ♪ In your row, she's dressed in yellow ♪ ♪ She says, "Hello" ♪ ♪ "Come sit next to me, you fine fellow" ♪ ♪ You run over there without a second to lose ♪ ♪ And what comes next, hey ♪ ♪ Bust a move ♪ ♪ You want it ♪ (..)2016 TvShow: The Big Bang Theory Title: The Positive Negative Reaction Season: 9 Episode 16