- a rogue; rascal; scoundrel: That son of a gun still owes me $20.
- a tiresome or disagreeable matter, chore, etc.
- (used as an affectionate greeting, term of address, etc.): Charlie Humpelmeyer, you old son of a gun, how are you?
- (used as an exclamation of irritation, surprise, dismay, etc.)
- a rogue or rascal: used as a jocular form of address
