shooter (Noun) — A person who shoots (usually with respect to their ability to shoot). ex. "a poor shooter"
shooter (Noun) — A large marble used for shooting in the game of marbles.
shooter (Noun) — A gambler who throws dice in the game of craps.
shooter (Noun) — (sport) a player who drives or kicks a ball at the goal (or a basketball player who shoots at the basket).
shooter (Noun) — A professional killer who uses a gun.