rotor

noun

• a rotary part of a machine or vehicle, in particular.
• a hub with a number of radiating airfoils that is rotated in an approximately horizontal plane to provide the lift for a rotary-wing aircraft.
• the rotating assembly in a turbine, especially a wind turbine.
• the armature of an electric motor.
• the rotating part of the distributor of an internal combustion engine that successively makes and breaks electrical contacts so that each spark plug fires in turn.
• the rotating container in a centrifuge.
• the rotary winder of a clockwork watch.
• Meteorology a large eddy in which the air circulates around a horizontal axis, especially in the lee of a mountain.