1866, from French aéroplane (1855), from Greek aero- "air" (see air, n.1) + stem of French planer "to soar," from Latin planus "level, flat" (see plane, n.1). Originally in reference to surfaces (such as the protective shell casings of beetles' wings); meaning "heavier than air flying machine" first attested 1873, probably an independent English coinage (see airplane).