fellow in WordNet English dictionary

1. a friend who is frequently in the company of another
   "drinking companions"; "comrades in arms"
   companion  comrade  fellow  familiar  associate 
   
2. a man who is the lover of a girl or young woman
   "if I'd known he was her boyfriend I wouldn't have asked"
   boyfriend  fellow  beau  swain  young man 
   
3. a boy or man
   "that chap is your host"; "there's a fellow at the door"; "he's a likable cuss"; "he's a good bloke"
   chap  fellow  feller  fella  lad  gent  blighter  cuss  bloke 
   
4. an informal form of address for a man
   "Say, fellow, what are you doing?"; "Hey buster, what's up?"
   fellow  dude  buster 
   
5. a person who is member of one's class or profession
   "the surgeon consulted his colleagues"; "he sent e-mail to his fellow hackers"
   colleague  confrere  fellow 
   
6. a member of a learned society
   "he was elected a fellow of the American Physiological Association"
   fellow 
   
7. one of a pair
   "he lost the mate to his shoe"; "one eye was blue but its fellow was brown"
   mate  fellow