autogiro
Concise Oxford English Dictionary © 2008 Oxford University Press:
autogiro /ɔːtəʊˈʤʌɪrəʊ/ (also autogyro)
▶noun (pl. autogiros) a form of aircraft with unpowered freely rotating horizontal blades and a propeller.
– origin 1920s: from Sp., from auto- ‘self’ + giro ‘gyration’.
'autogiro' also found in these Oxford entries:

