Entry 1 sense Webster, 1913 Rotor /rōt'-ẽr/ · Ro·tor · IPA /ˈɹoʊ.tɚ/ 01 n. The rotating part of a generator or motor. Contrasted with stator, the stationary part. 1. The rotating part of a generator or motor. Contrasted with stator, the stationary part.(Elec.)