Aileron

Ai"le*ron, n. [F., dim. of aile wing.]

1.

Defn: A half gable, as at the end of a penthouse or of the aisle of a church.

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.