son of a gun noun a fellow UK,1708 Originally, “a soldier’s bastard”, now mildly disparaging or pejorative. Occasionally used as an exclamation of surprise.
What made you think I wanted to keep you around / While I work my ass off while you just lounge around, huh? / You slump, bum, son of a gun, / And uh, How much you worth? I think negative, done. — Missy Elliott, SonofaGun(Remix), 2001