A part or surface, such as a wing, propeller blade, or rudder, whose shape and orientation control stability, direction, lift, thrust, or propulsion.

A structure having a shape that provides lift, propulsion, stability, or directional control in a flying object. An aircraft wing provides lift by causing air to pass at a higher speed over the wing than below it, resulting in greater pressure below than above. Propellers are airfoils that are spun rapidly to provide propulsion. See more at Bernoulli effect, See Note at aerodynamics.