noun
also au·to·gy·ro ˌȯd.]ōˈjī(ˌ)rō, ˌȯt], ]əˈ-, ˈ ̷ ̷ ̷ ̷ˌ ̷ ̷(ˌ) ̷ ̷\
( -s )
Etymology: from Autogiro, a trademark
: a rotating-wing aircraft that achieves slow flight and vertical takeoff by the use of a freely rotating rotor replacing or supplementing the wings but is driven forward by a conventional propeller — compare helicopter
[s]autogiro.jpg[/s]