*spoiler*

n. 1. One who spoils; a plunderer; a pillager; a robber; a despoiler. [ 1913 Webster ]

2. One who corrupts, mars, or renders useless. [ 1913 Webster ]

3. (Aeronautics) A device attached to the wing of an airplane or other airfoil, which breaks the smooth flow of air during flight and decreases the lift of the airfoil; -- used to control the attitude of the airplane during banking or descent. [ PJC ]

4. A device attached to a car to decrease lift and increase traction, usually shaped as a flat surface and attached above the rear of the car, and working on the same principal as the aircraft spoiler{ 3 }. [ PJC ]