views updated May 23 2018

ro·tor / ˈrōtər/ • n. 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, esp. 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. ∎  Meteorol. a large eddy in which the air circulates around a horizontal axis, esp. in the lee of a mountain.