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

Example Sentences

Recent Examples on the Web That will involve repairing or replacing their generators, gearboxes, the hydraulic systems that control their rotor blades, and transformers that regulate their electrical output, as needed, the utility said. oregonlive, 17 Jan. 2023 The autogiro had a typical propeller for forward flight as well as an un-powered rotor blade to provide lift. Alice George, Smithsonian Magazine, 11 Jan. 2023 The passenger then squeezes the edge of the pilot's seat to brace as the cockpit is sprayed with broken glass after one of the second helicopter's rotor blades strikes the windshield. Arkansas Online, 7 Jan. 2023 All but three of the cars built were powered by a Wankel, debuting with a three-rotor unit. Robert Ross, Robb Report, 25 Aug. 2022 The onshore wind turbine market is dominated by an industry standard three-rotor HAWT design, but there is no standard design for VAWTs. Ariel Cohen, Forbes, 20 May 2021 But the presence of a three-rotor machine suggests that at least one surface ship’s officers also threw their Enigma machine overboard in the final days of the war. Kiona N. Smith, Ars Technica, 27 Dec. 2020 The vehicle has a highly versatile, dual-rotor design and is engineered to be low-cost and easily extensible/modifiable. IEEE Spectrum, 31 May 2019 This is possible because of a small motor with rotor blades—typically used for drones—that is inserted into the soft tubular structure. IEEE Spectrum, 3 Feb. 2023 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 31 Mar. 2023.

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

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Challenging Standardized Test Words, Vol. 2

  • a pencil broken in half on top of a test answer sheet
  • The business’s new computer system proved not to be a panacea.
Spell It

Hear a word and type it out. How many can you get right?

Solve today's spelling word game by finding as many words as you can with using just 7 letters. Longer words score more points.

Can you make 12 words with 7 letters?