- any of various rotating mechanical parts; specif.,
- the rotating part of a motor, dynamo, etc.
- in the distributor of a gasoline engine, the part that momentarily connects each spark plug wire to the high voltage from the coil
- in disc brakes, the part to which the wheel is usually mounted
- a system of airfoils, together with their hub, that rotates around a vertical axis, as on a helicopter
contr. of rotator