Definify.com
Webster 1913 Edition
Propeller
Pro-pel′ler
,Noun.
1.
One who, or that which, propels.
2.
A contrivance for propelling a steam vessel, usually consisting of a screw placed in the stern under water, and made to revolve by an engine; a propeller wheel.
3.
A steamboat thus propelled; a screw steamer.
Propeller wheel
,the screw, usually having two or more blades, used in propelling a vessel.