副翼
Aileron \Ai"le*ron\, n. [F., dim. of aile wing.] 1. A half gable, as at the end of a penthouse or of the aisle of a church. 2. (A["e]ronautics) 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.
aileron n : an airfoil that controls lateral motion