rotor

American  

[roh-ter] / ˈroʊ tər /

noun

• rotors
  plural

1. Electricity. a rotating member of a machine.

2. Aeronautics. a system of rotating airfoils, as the horizontal ones of a helicopter or of the compressor of a jet engine.

3. any of a number of tall, cylindrical devices mounted on a special ship rotor ship and rotated in such a way that the Magnus effect of wind impinging on the cylinders is used to drive and maneuver the vessel.

4. (in a self-winding watch) a weight eccentrically mounted on an arbor for keeping the mainspring wound.

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rotor British  

/ ˈrəʊtə /

noun

1. the rotating member of a machine or device, esp the armature of a motor or generator or the rotating assembly of a turbine Compare stator

2. a device having blades radiating from a central hub that is rotated to produce thrust to lift and propel a helicopter

3. the revolving arm of the distributor of an internal-combustion engine

4. a violent rolling wave of air occurring in the lee of a mountain or hill, in which the air rotates about a horizontal axis

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Other Word Forms

Noun Inflected Forms

• rotors
  plural

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Etymology

Origin of rotor

First recorded in 1873; short for rotator

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Example Sentences

See Examples For:

rotor rotors

Its system also quietens things down through slower rotor speed and by using materials that reduce vibration noise.

From BBC ● Oct. 28, 2026

One of Lynn’s former colleagues told him they saw a tail rotor on the ground, and Lynn quickly learned it was Moreno and Marciniw who were onboard.

From Los Angeles Times ● Sep. 19, 2026

Video of the incident emerged showing the cockpit apparently becoming detached from the rotor.

From Barron's ● Jul. 16, 2026

Videos posted on Facebook from Long Beach also showed flashes and bangs in neighborhoods, and the loud rotor of a helicopter overhead.

From Los Angeles Times ● Jun. 6, 2026

So when we figure out the rotor positions for one day, we only have to check 32 positions the next day.

From "The Bletchley Riddle" by Ruta Sepetys and Steve Sheinkin

The light design of the rotors also means that if there is an engine failure, the light blades can lose their momentum in rotation quickly, Cress said.

From Los Angeles Times ● Sep. 17, 2026

Aerial footage showed a large fire that appeared to involve shipping containers and cars, and the wreckage of a helicopter, whose mangled tail and rotors could be seen in the flames.

From Barron's ● Sep. 16, 2026

They're shaped like a large bullet and propelled by four rotors at the base.

From BBC ● May 21, 2026

An International Trade Commission study in 2019 found that Chinese production of automotive parts had grown significantly over the preceding decade, with U.S. imports concentrated in smaller components such as brake rotors.

From The Wall Street Journal ● May 9, 2026

The drumbeat of the rotors became a loud, high-pitched whine as the chopper circled lower.

From "Flush" by Carl Hiaasen

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