the continuous rotation of a body in an airflow, such as that of the rotor blades of a helicopter in an unpowered descent
autorotation in American English
(ˌɔtourouˈteiʃən)
noun
Aeronautics
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
Derived forms
autorotational
adjective
Word origin
[1915–20; auto-1 + rotation]This word is first recorded in the period 1915–20. Other words that entered Englishat around the same time include: GI, camouflage, collage, decoder, stockpileauto- is a combining form meaning “self,” “same,” “spontaneous,” used in the formationof compound words. Other words that use the affix auto- include: autoclave, autoignition, autoinfection, autonomous, autostability