1. A type of aircraft with a single large horizontal rotor that provides lift and one or more propellers that provide forward thrust.
Usage: Also spelled autogyro.; The rotor is not powered; it rotates freely as the aircraft moves forward.; Precursor to the modern helicopter.

Examples

• The autogiro was invented in Spain in the 1920s by Juan de la Cierva.
• Unlike a helicopter, the autogiro's rotor is unpowered and spins due to air flowing through it.
• Early autogiros could take off in shorter distances than conventional airplanes.
• The autogiro represents an important step in the development of rotorcraft technology.
• Pilots appreciated the autogiro's ability to descend steeply without stalling.