Airfoil

Any device that creates a force, or lift, based on Bernoulli’s principles or Newton’s laws, when air is caused to flow over the surface of the device.

Aviation Maintenance Technician Handbook — General, p. G-1

Also defined in 3 more sources

Any surface designed to obtain a useful reaction, or lift, from air passing over it.

Aviation Maintenance Technician Handbook — Airframe, p. G-2

Any surface designed to obtain a useful reaction of lift, or negative lift, as it moves through the air.

Helicopter Flying Handbook, p. G-1

Any surface, such as a wing, propeller, rudder, or even a trim tab, which provides aerodynamic force when it interacts with a moving stream of air.

Pilot's Handbook of Aeronautical Knowledge, p. G-2

Taught in AF-N Quick reference, GEN-J Quick reference.