rotor

R1O1T1O1R1
UK/ˈɹəʊ.tə/US/ˈɹoʊ.tɚ//ˈɹoʊ.tə/

noun

A rotating part of a mechanical device; for example, in an electric motor, generator, alternator, or pump.

Similar
rotary wingrotor coil
Opposite
Less commonFirst used 1900sScrabble 5

Meanings

nounrotor (plural rotors)

plural rotors

  1. A rotating part of a mechanical device; for example, in an electric motor, generator, alternator, or pump.First known use 1900s

    Turbines have been around for a long time—windmills and water wheels are early examples. The name comes from the Latin turbo, meaning vortex, and thus the defining property of a turbine is that a fluid or gas turns the blades of a rotor, which is attached to a shaft that can perform useful work.

    2013 July-August, Lee S. Langston, “The Adaptable Gas Turbine”, in American Scientist, archived from the original on 07 Sep 2013
    1. automotiveIn a disc brake, the metal disc attached to the wheel hub.
    2. aeronauticsThe wing of a helicopter or other rotary wing aircraft (e.g., heli-type drone).

      Synonyms: rotary wing

  2. climatologyA type of powerful horizontal-axis atmospheric vortex generated by the interaction of strong winds with mountainous terrain.

    A glider instructor, who had been in the COS area for more than 25 years, was interviewed. He stated that around 1200 on the day of the accident, he observed a rotor hit the ground with estimated wind speeds of 70 to 80 miles per hour.

    2001, National Transportation Safety Board, “1.7.1 Observations and Forecasts”, in Uncontrolled Descent and Collision With Terrain, United Airlines Flight 585, Boeing 737-200, N999UA, 4 Miles South of Colorado Springs Municipal Airport, Colorado Springs, Colorado, March 3, 1991, archived from the original on 22 Jan 2021, pages 30–31
  3. algebraA quantity having magnitude, direction, and position.

    These quantities are unit lengths measured anywhere on the axes in the positive directions. They have magnitude, direction, and position, and are thus what I have called rotors (short for rotators) to distinguish them from vectors, which have magnitude and direction but no position.

    1878, William Kingdon Clifford, “Applications of Grassmann's Extensive Algebra”, in American Journal of Mathematics, volume 1, number 4, →DOI, →ISSN, page 353
  4. cellular automataThe set of cells within an oscillator that switch between being alive and dead over the course of the oscillator's period.

    The following figure shows examples of the most versatile class of these oscillators. The first emulates the p10 shown above; the second has period 62 and a rotor of size 10.

    1997 November 30, David Bell, “Day & Night - An Interesting Variant of Life (part 2/5)”, in comp.theory.cell-automata (Usenet)
    2 more examples

    The problem of determining the asymptotic colouring for a cyclic pattern from a given initial black and white pattern is completely solved. The analysis leads to the proposal of the distinction between primary and secondary rotor cells (i.e. a refinement of the classical stator-rotor distinction).

    1998 March 18, Gunnar Johnsson, “Genetic aspects of the Game of Life.”, in comp.theory.cell-automata (Usenet)

    In B37/S23, it goes symmetrical after 10 ticks, and produces a familiar pair of B-heptominoes after 23 ticks (the next generation after this can be found in the rotor of a standard B3/S23 p46 oscillator):

    2008 June 25, Dave Greene, “Life: B37/S23 - A Chaotic Universe.”, in comp.theory.cell-automata (Usenet)
  5. An amusement park and carnival ride consisting of a rotating cylindrical chamber in which centrifugal force adheres riders to the wall as the floor drops away, creating a sensation of defying gravity.

Synonyms & antonyms

nounThe wing of a helicopter or other rotary wing aircraft (e.g., heli-type drone).

Narrower

More synonyms by meaning

nounthe rotating armature of a motor or generator

Similar
rotor coil
Opposite
Broader

Synonym sets from Open English WordNet, CC BY 4.0.

Origin

From an irregular clipping of rotator, originally in mathematics, coined by English mathematician and philosopher William Kingdon Clifford based on vector, see quotations. Doublet of rota and ruote.

Full word history & related roots →

Translations

Arabic عَمُود نَاقِل الْحَرَكَة
  • عَمُود نَاقِل الْحَرَكَة (ʕamūd nāqil al-ḥaraka)a rotating part of a mechanical device
Basque errotore
  • errotorea rotating part of a mechanical device
Bulgarian ротор, перка
  • ротор (rotor)the wing of a helicopter or similar
  • перка (perka)the wing of a helicopter or similar
  • ротор (rotor)a rotating part of a mechanical device
Chinese Mandarin 旋翼, 主旋翼
  • 旋翼 (xuányì)the wing of a helicopter or similar
  • 主旋翼 (zhǔ xuányì)the wing of a helicopter or similar
  • 轉子 /转子 (zhuànzǐ)a rotating part of a mechanical device
Czech rotor
  • rotora rotating part of a mechanical device
Finnish roottori, roottori
  • roottorithe wing of a helicopter or similar
  • roottoria rotating part of a mechanical device
  • pyörijäa rotating part of a mechanical device
French rotor
  • rotora rotating part of a mechanical device
German Hauptrotor, Rotor
  • Hauptrotorthe wing of a helicopter or similar
  • Rotora rotating part of a mechanical device
Greek δρομέας
  • δρομέας (droméas)a rotating part of a mechanical device
Italian rotore, pala
  • rotorethe wing of a helicopter or similar
  • palathe wing of a helicopter or similar
  • rotorea rotating part of a mechanical device
Japanese ローター, 回転子
  • ローター (rōtā)a rotating part of a mechanical device
  • 回転子 (kaitenshi)a rotating part of a mechanical device
Māori paetāwhirowhiro
  • paetāwhirowhiroa rotating part of a mechanical device
Norwegian rotor
  • rotora rotating part of a mechanical device
Polish wirnik, śmigło
  • wirnikthe wing of a helicopter or similar
  • śmigłothe wing of a helicopter or similar
  • wirnika rotating part of a mechanical device
  • rotora rotating part of a mechanical device
Portuguese hélice, rotor
  • hélicethe wing of a helicopter or similar
  • rotora rotating part of a mechanical device
Romanian elice, rotor
  • elicethe wing of a helicopter or similar
  • rotora rotating part of a mechanical device
Russian ро́тор, несу́щий винт
  • ро́тор (rótor)the wing of a helicopter or similar
  • несу́щий винт (nesúščij vint)the wing of a helicopter or similar
  • ро́тор (rótor)a rotating part of a mechanical device
Spanish hélice, rotor
  • hélicethe wing of a helicopter or similar
  • rotora rotating part of a mechanical device
Tagalog painog
  • painoga rotating part of a mechanical device
Ukrainian ро́тор
  • ро́тор (rótor)a rotating part of a mechanical device

Rhymes & wordplay

Sounds the same

rotaRota (non-rhotic)Rhoda (non-rhotic, flapping)
Cite this entry
APA

rotor. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/rotor

MLA

“rotor.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/rotor. Accessed November 3, 2026.

Chicago

WatkinsX Dictionary, s.v. “rotor,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/rotor.

Source: rotor on Wiktionary, CC BY-SA 4.0.