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 That side-to-side movement caused the helicopter’s main rotor to strike the flight deck, which in turn led to the helicopter going over the side of the ship. Andrew Dyer, San Diego Union-Tribune, 7 Sep. 2021 Two Apache helicopter gunships flew low, seeking to scare some people away from the plane or push them off with their powerful rotor wash., 17 Aug. 2021 Cartier has created a platinum automatic skeleton watch in which the rotor houses the entire movement—mainspring, escapement, and all. Charles Curkin, ELLE Decor, 12 Apr. 2022 For this to happen, the rotor rotates in both directions at an irregular speed. Paige Reddinger, Robb Report, 30 Mar. 2022 And in spite of hitting a top speed of only 250 rpm, the fan is even more well-balanced than the rotor of a turbocharger. Jonathan M. Gitlin, Ars Technica, 21 Mar. 2022 Videos taken by witnesses showed a rotor blade separating from the first Black Hawk and striking the second Black Hawk, according to a Utah National Guard spokesman. Scott D. Pierce, The Salt Lake Tribune, 2 Mar. 2022 The 21-year-old sailor threw off the protective helmet everyone wears on the flight line and ran toward the spinning rear tail rotor of an HM-60S helicopter. Washington Post, 15 Nov. 2021 This approach also gives the engineers an extra knob to turn, as the power electronics can continuously alter the strength of this unique rotor's magnetic field. Dan Edmunds, Car and Driver, 1 Mar. 2022 See More

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.

First Known Use of rotor

1892, in the meaning defined at sense 1a

History and Etymology for rotor

contraction of rotator

Learn More About rotor

Dictionary Entries Near rotor



rotor blade

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Statistics for rotor

Last Updated

24 May 2022

Cite this Entry

“Rotor.” Dictionary, Merriam-Webster, Accessed 28 May. 2022.

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More Definitions for rotor


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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