Wikipedia, Apr. 11, 2013 (An airplane (also known as an aeroplane in British English or simply a plane) is a powered fixed-wing aircraft that is propelled forward by thrust from a jet engine or propeller.)

Merriam-Webster online, Apr. 11, 2013 (airplane: a powered heavier-than-air aircraft with fixed wings from which it derives most of its lift. Synonyms: aeroplane [chiefly British], plane)

Dictionary.com, Apr. 11, 2013 (airplane 1. a heavier-than-air aircraft kept aloft by the upward thrust exerted by the passing air on its fixed wings and driven by propellers, jet propulsion etc. 2. any similar heavier-than-air aircraft, as a glider or helicopter.)