the rotating armature of a motor or generator
"The mechanic had to replace the worn rotor inside the car's starter motor because it was sparking and failing to turn the engine over."
the revolving bar of a distributor
"When I held up the old engine part, my mechanic immediately pointed to the spinning rotor as the piece responsible for directing the electrical current in the distributor."
rotating mechanism consisting of an assembly of rotating airfoils
"there are horizontal rotors on a helicopter or compressor rotors in a jet engine"
A rotating part of a mechanical device, for example in an electric motor, generator, alternator or pump.
"The technician noticed that the damaged rotor was preventing the electric motor from starting properly."