ro·​tor ˈrō-tər How to pronounce rotor (audio)
: a part that revolves in a stationary part
a brake rotor
: the rotating member of an electrical machine
: an assembly of rotating blades that supplies lift or stability for a rotorcraft

Examples of rotor in a Sentence

Recent Examples on the Web Zero porpoises passed through the areas while the rotors were in motion. Discover Magazine, 16 Feb. 2024 Wind farms in Quebec started doing this in 2011: If the grid is short of power and the AC frequency starts to drop, wind farms can briefly boost their output by as much as 6 percent through a collaboration between the turbines’ solid-state power electronics and their rotors. IEEE Spectrum, 14 Feb. 2024 Thus, Ingenuity was fitted with rotor blades that are larger and spin far more rapidly than would be needed on Earth for a similar craft of its size. Joey Roulette and Steve Gorman, The Christian Science Monitor, 26 Jan. 2024 For those that like to see behind the curtain, the movement’s 21-karat gold central rotor and its horological sleights of hand can be seen through the transparent caseback. Demetrius Simms, Robb Report, 2 Jan. 2024 The white main rotor blade was fractured found in an adjacent field. CBS News, 5 Feb. 2024 The rotors on Ingenuity spun fast, with their tips moving at a speed of Mach 0.65, or 65 percent of the speed of sound on the surface of Mars. Eric Berger, Ars Technica, 29 Jan. 2024 Ingenuity, resembling a box with four legs and parasol of rotor blades and solar panel, will live out its final days idle but emitting periodic blips of data before losing contact with the rover as Perseverance moves farther away. Joey Roulette and Steve Gorman, The Christian Science Monitor, 26 Jan. 2024 Images beamed back this week from its last flight showed that one or more of its rotor blades suffered damage while landing and may have hit the surface. Democrat-Gazette Staff From Wire Reports,, 26 Jan. 2024 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'rotor.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


contraction of rotator

First Known Use

1892, in the meaning defined at sense 1a

Time Traveler
The first known use of rotor was in 1892

Dictionary Entries Near rotor

Cite this Entry

“Rotor.” Dictionary, Merriam-Webster, Accessed 3 Mar. 2024.

Kids Definition


ro·​tor ˈrōt-ər How to pronounce rotor (audio)
: a part that rotates in a stationary part (as in an electrical machine)
: a complete system of rotating blades that support a helicopter in flight

More from Merriam-Webster on rotor

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