autorotation: Meaning and Definition of

au•to•ro•ta•tion

Pronunciation: (ô"tō-rō-tā'shun), [key]
— n. Aeron.
  1. the condition of flight occurring when lift is derived solely from the action of air upon the unpowered rotor of a moving helicopter or autogiro.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.