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