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]
(..) get caught, that's all. If you find something, you've got a murderer, and they don't care anything about house rules. If you don't find anything, the fellow's clear. At the risk of sounding stuffy, I'd like to remind you of the Constitution... and the phrase, ''search warrant (..)1954 Rear Window
(..) I'll keep an eye on the alley. Long distance. You didn't see the killing or the body. How do you know there was a murder? Everything this fellow's done has been suspicious! trips at night in the rain, knives and saws and trunks with rope, and now this wife that isn't there anymore. (..)1954 Rear Window