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[pur-ter-bey-shuh n] /ˌpɜr tərˈbeɪ ʃən/
the act of perturbing.
the state of being perturbed.
mental disquiet, disturbance, or agitation.
a cause of mental disquiet, disturbance, or agitation.
Astronomy. deviation of a celestial body from a regular orbit about its primary, caused by the presence of one or more other bodies that act upon the celestial body.
Origin of perturbation
1325-75; < Latin perturbātiōn- (stem of perturbātiō; see perturb, -ation); replacing Middle English perturbacioun < Anglo-French < Latin, as above
Related forms
perturbational, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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Examples from the Web for perturbation
Contemporary Examples
Historical Examples
  • In the case of the world, the perturbation is very slight, and amounts only to a reversal of motion.

    Statesman Plato
  • Other than this there was no 347 sign of perturbation on its owner's part.

    Fair Harbor

    Joseph Crosby Lincoln
  • In spite of his perturbation he had been amused for the moment.

    Cap'n Dan's Daughter Joseph C. Lincoln
  • Hephzy seized the opportunity to express to me her perturbation.

    Kent Knowles: Quahaug Joseph C. Lincoln
  • It was not sorrow, and it was not pain; it was anxiety, uncertainty, perturbation.

    A Son of Hagar

    Sir Hall Caine
  • Failing to stir a smile, poor fellow, he made no secret of his perturbation.

    The Symposium Xenophon
  • With each instant the perturbation of the Grand Duchess grew.

    The Princess Virginia C. N. Williamson
  • He stopped, and turned away from her, concealing his perturbation.

    Gilian The Dreamer Neil Munro
  • The girl observed his perturbation and shrewdly guessed the reason.

    Gilian The Dreamer Neil Munro
British Dictionary definitions for perturbation


the act of perturbing or the state of being perturbed
a cause of disturbance or upset
(physics) a secondary influence on a system that modifies simple behaviour, such as the effect of the other electrons on one electron in an atom
(astronomy) a small continuous deviation in the inclination and eccentricity of the orbit of a planet or comet, due to the attraction of neighbouring planets
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for perturbation

late 14c., from Old French perturbacion "disturbance, confusion" (14c.) and directly from Latin perturbationem (nominative perturbatio) "confusion, disorder, disturbance," noun of action from past participle stem of perturbare (see perturb).

Online Etymology Dictionary, © 2010 Douglas Harper
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perturbation in Science
  1. A small change in a physical system, most often in a physical system at equilibrium that is disturbed from the outside.

  2. Variation in a designated orbit, as of a planet, that results from the influence of one or more external bodies. Gravitational attraction between planets can cause perturbations and cause a planet to deviate from its expected orbit. Perturbations in Neptune's orbit led to the discovery of the object that was causing the perturbation—the planet Pluto. Perturbations in the orbits of stars have led to the discovery of planetary systems outside of our Solar system.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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