rotor

noun

ro·​tor ˈrō-tər 

1

a

: a part that revolves in a stationary part

a brake rotor

b

: the rotating member of an electrical machine

2

: an assembly of rotating blades that supplies lift or stability for a rotorcraft

Examples of rotor in a Sentence

Recent Examples on the Web

To complete the warm golden hues, the automatic movement is topped with a 22-karat gold rotor, which glows through the caseback. —Carol Besler, Forbes.com, 20 Jan. 2026

Drone supply chains are complex, from the rare-earth minerals like neodymium and dysprosium required to build magnets and motors to the composite frames that hold rotors and cameras. —Jared Perlo, NBC news, 18 Jan. 2026

Smooth stopping power is provided by hydraulic disc brakes at each wheel sporting 180-mm rotors, with motor cut-off. —New Atlas, 16 Jan. 2026

The turbine rotor sits about 570 feet (174 m) above water level, and construction was completed using a fourth-generation vessel with a 2,000-ton lifting capacity. —Ameya Paleja, Interesting Engineering, 13 Jan. 2026

Word History

Etymology

contraction of rotator

First Known Use

1892, in the meaning defined at sense 1a

Phrases Containing rotor

• tilt-rotor

Rhymes for rotor

• boater
• floater
• motor
• voter
• locomotor
• psychomotor
• servomotor
• vasomotor
• oculomotor
• sensorimotor
• premotor
• promoter

Kids Definition

rotor

noun

ro·​tor ˈrōt-ər 

1

: a part that rotates in a stationary part (as in an electrical machine)

2

: a complete system of rotating blades that support a helicopter in flight