AILERON

Ai″le‐ron (?), n. [[F., dim. of aile wing.]] 1. 1. A half gable, as at the end of a penthouse or of the aisle of a church.
2. 2. (Aëronautics) A small plane or surface capable of being manipulated by the pilot of a flying machine to preserve or destroy lateral balance; a hinged wing tip; a lateral stabilizing or balancing plane.