[syn: gunman, gunslinger, hired gun, gun, gun for hire, triggerman, hit man, hitman, torpedo, shooter]
The Collaborative International Dictionary of English v.0.48:
Shooter \Shoot"er\, n.
   1. One who shoots, as an archer or a gunner.
      [1913 Webster]
   2. That which shoots. Specifically:
      (a) A firearm; as, a five-shooter. [Colloq. U.S.]
      (b) A shooting star. [R.]
          [1913 Webster]
WordNet (r) 3.0 (2006):
shooter
    n 1: a large marble used for shooting in the game of marbles
         [syn: taw, shooter]
    2: a person who shoots (usually with respect to their ability to
       shoot); "he is a crack shot"; "a poor shooter" [syn: shot,
       shooter]
    3: a gambler who throws dice in the game of craps [syn:
       shooter, crap-shooter]
    4: (sports) a player who drives or kicks a ball at the goal (or
       a basketball player who shoots at the basket)
    5: a professional killer who uses a gun [syn: gunman,
       gunslinger, hired gun, gun, gun for hire,
       triggerman, hit man, hitman, torpedo, shooter]