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

Since the energy storage involves no chemical conversion, there is no risk of degradation of the rotor even after many years. — Ameya Paleja, Interesting Engineering, 22 Sep. 2026

Braking performance for the KB998 Rimini began to fade after multiple 20- to 30-minute sessions, something of a surprise given the Brembo 330-millimeter rotors and M50 monobloc calipers. — Michael Van Runkle, Robb Report, 21 Sep. 2026

In the aerial footage shot by Moreno and Marciniw, the sound of the engine’s motor winds down and a horn blares, possibly warning the pilot that the main rotor speed had dropped too low or the helicopter had lost hydraulics. — Andrew J. Campa, Los Angeles Times, 19 Sep. 2026

Jeff Guzzetti, a former NTSB and FAA investigator, also told the Times that the horn sound was probably a low rotor RPM alarm, suggesting a mechanical problem before the helicopter crashed. — David Chiu, PEOPLE, 17 Sep. 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
• coater
• floater
• motor
• voter
• locomotor
• psychomotor
• servomotor
• vasomotor
• oculomotor
• sensorimotor
• premotor

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