ro·​tor | \ ˈrō-tər How to pronounce rotor (audio) \

Definition of rotor

1a : 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 The turning diameter of its rotor is longer than two American football fields end to end. New York Times, "A Monster Wind Turbine Is Upending an Industry," 1 Jan. 2021 From 1942 onward, U-boats carried a four-rotor model of the Enigma device. Kiona N. Smith, Ars Technica, "Divers recover a WWII Enigma Machine from the Baltic Sea," 27 Dec. 2020 Everything underneath is all custom—just like the Hoonicorn: a tube-frame chassis, billet four-rotor engine, sequential gearbox, all-wheel drive, and a massive Garrett turbo. Maxwell B. Mortimer, Car and Driver, "Ken Block's 1400-HP Hoonicorn, Rob Dahm's 1400-HP RX-7 to Face Off," 11 Dec. 2020 Dahm is bringing a quad-rotor Mazda RX-7 to this race, which will take place on social media next week. Maxwell B. Mortimer, Car and Driver, "Ken Block's 1400-HP Hoonicorn, Rob Dahm's 1400-HP RX-7 to Face Off," 11 Dec. 2020 Four-rotor Enigmas, meanwhile, have sold for upward of $400,000 at major auction houses. Nora Mcgreevy, Smithsonian Magazine, "Divers Discover Nazi Enigma Machine Thrown Into the Baltic Sea During WWII," 7 Dec. 2020 In a disc brake, fluid pushing into the brake caliper is what moves your brake pads inward to clamp down on the rotor and slow the car using that friction. Mike Allen, Popular Mechanics, "How to Bleed Your Brakes the Right Way," 8 Oct. 2020 There is also a new dashboard display to report rotor and brake fluid temperatures. Mike Duff, Car and Driver, "The STO Is the Ultimate Huracán," 25 Nov. 2020 The United Nations International Maritime Organization has set ambitious decarbonization goals involving marine fuels, and the European Union is now funding rotor research. Lynn Freehill-maye, Scientific American, "Rotating Sails Help to Revive Wind-Powered Shipping," 23 Nov. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'rotor.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of rotor

1892, in the meaning defined at sense 1a

History and Etymology for rotor

contraction of rotator

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Time Traveler for rotor

Time Traveler

The first known use of rotor was in 1892

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Statistics for rotor

Last Updated

12 Jan 2021

Cite this Entry

“Rotor.” Dictionary, Merriam-Webster, Accessed 22 Jan. 2021.

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More Definitions for rotor


How to pronounce rotor (audio)

English Language Learners Definition of rotor

technical : a part of a machine that turns around a central point


ro·​tor | \ ˈrō-tər How to pronounce rotor (audio) \

Kids Definition of rotor

1 : the part of an electrical machine that turns
2 : a system of spinning horizontal blades that support a helicopter in the air

More from Merriam-Webster on rotor

Nglish: Translation of rotor for Spanish Speakers

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