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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. 2015.
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Examples from the Web for perturbation
Contemporary Examples
Historical Examples
  • In his perturbation he pushed back his chair, and the movement made her look up at him.

    The Reef Edith Wharton
  • In the case of the world, the perturbation is very slight, and amounts only to a reversal of motion.

    Statesman Plato
  • There was a pause--a dead pause, indeed; the baron changed colour and appeared to attempt to hide the perturbation of his spirit.

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

    Cap'n Dan's Daughter Joseph C. Lincoln
  • I needed but little encouragement; for the perturbation of my mind stood in want of this relief.

    Caleb Williams William Godwin
  • Hephzy seized the opportunity to express to me her perturbation.

    Kent Knowles: Quahaug Joseph C. Lincoln
  • Marianne's joy was almost a degree beyond happiness, so great was the perturbation of her spirits and her impatience to be gone.

    Sense and Sensibility Jane Austen
  • With each instant the perturbation of the Grand Duchess grew.

    The Princess Virginia C. N. Williamson
  • Here the squire heaved a sigh which told of the perturbation of his soul.

    Nestleton Magna J. Jackson Wray
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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