Aileron
Aileron (ā"le*ron) , noun
[French, dim. of aile wing.]
1.
A half gable, as at the end of a penthouse or of the aisle of a church.
2.
(Aeronautics) A small plane or surface capable of being manipulated by the pilot of a flying machine to control lateral balance; a hinged wing tip; a lateral stabilizing or balancing plane.