per·​turb | \ pər-ˈtərb How to pronounce perturb (audio) \
perturbed; perturbing; perturbs

Definition of perturb

transitive verb

1 : to cause to be worried or upset : disquiet, unsettle Half way down the next flight, she smiled to think that a char-woman's stare should so perturb her.— Edith Wharton The crowd didn't seem to perturb them in the slightest …— Nick Hornby
2 : to throw into confusion : disorder perturbing the social order
3 : to cause to experience a perturbation — see perturbation sense 2 Newton finally realized that the planetary orbits would be only approximate ellipses, for the mutual attractions of the planets would perturb their paths.— Owen Gingerich

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Other Words from perturb

perturbable \ pər-​ˈtər-​bə-​bəl How to pronounce perturbable (audio) \ adjective

Choose the Right Synonym for perturb

discompose, disquiet, disturb, perturb, agitate, upset, fluster mean to destroy capacity for collected thought or decisive action. discompose implies some degree of loss of self-control or self-confidence especially through emotional stress. discomposed by the loss of his beloved wife disquiet suggests loss of sense of security or peace of mind. the disquieting news of factories closing disturb implies interference with one's mental processes caused by worry, perplexity, or interruption. the discrepancy in accounts disturbed me perturb implies deep disturbance of mind and emotions. perturbed by her husband's strange behavior agitate suggests obvious external signs of nervous or emotional excitement. in his agitated state we could see he was unable to work upset implies the disturbance of normal or habitual functioning by disappointment, distress, or grief. the family's constant bickering upsets the youngest child fluster suggests bewildered agitation. his declaration of love completely flustered her

Did You Know?

With its per- prefix, perturb meant originally "thoroughly upset", though today the word has lost most of its intense edge. Perturb and perturbation are often used by scientists, usually when speaking of a change in their data indicating that something has affected some normal process. When someone is referred to as imperturbable, it means he or she manages to remain calm through the most trying experiences.

Examples of perturb in a Sentence

It perturbed him that his son was thinking about leaving school. the caller's strange remark perturbed me enough to keep me awake that night
Recent Examples on the Web Let the right one insulin: The aggressive increase in insulin pricing continues to perturb lawmakers, including Rep. Kelly Butler, a Pennsylvania Republican. cleveland, "Study finds millions in Flyover country could lose health coverage if ACA is nixed: The Flyover," 7 Oct. 2019 Arnold, perturbed that the military dismissed his account, did interviews with local press. Matt Blitz, Popular Mechanics, "Angels, Airships, and Aliens: The 3,500-Year History of UFO Sightings," 24 Sep. 2019 According to this theory, over time, the black holes sink to the center of the cluster, perturbing one another’s orbits in complicated ways and, occasionally, entering tight enough orbits to collide. Quanta Magazine, "Latest Black Hole Collision Comes With a Twist," 1 June 2017 By controlling the elements within these ecosystems, scientists can understand how the real-world equivalents operate—and can be perturbed—in isolation. Robin George Andrews, Scientific American, "Can Spaceflight Save the Planet?," 6 Sep. 2019 Fitch coached in his grating style, perturbing many of the players. Gary Washburn,, "Bill Fitch’s last coaching job may have been his best," 4 Sep. 2019 Still, fears are growing about a global slowdown as the U.S. economic expansion breaks records, even if Snyder doesn’t appear perturbed by the prospect. Los Angeles Times, "How the rich get spending money: Locking fine art in storage and borrowing against it," 1 Aug. 2019 In exchange for that $30 million annual compensation, Federer—who, to his immense credit, always seems present and never perturbed by his off-court obligations—will make an appearance at a Uniqlo store, put on a smile and sign a few things. Daniel Rapaport,, "TennisCon: An Inside Look Into the Frenetic Week Before the U.S. Open," 28 Aug. 2019 Some Medinah members might be perturbed that the course record fell twice — Hideki Matsuyama shot 63 (twice, actually) and Thomas fired a 61 that featured a hole-out from 180 yards. Teddy Greenstein,, "5 takeaways from a ‘spectacular ’ BMW Championship, including crazy-low scores, a tough act for Olympia Fields to follow and Tiny Houses are here to stay," 18 Aug. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'perturb.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of perturb

14th century, in the meaning defined at sense 1

History and Etymology for perturb

Middle English, from Middle French perturber, from Latin perturbare to throw into confusion, from per- + turbare to disturb — more at turbid

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Statistics for perturb

Last Updated

18 Nov 2019

Time Traveler for perturb

The first known use of perturb was in the 14th century

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More Definitions for perturb


How to pronounce perturb (audio)

English Language Learners Definition of perturb

: to cause (someone) to be worried or upset


per·​turb | \ pər-ˈtərb How to pronounce perturb (audio) \
perturbed; perturbing

Kids Definition of perturb

: to disturb in mind : trouble greatly

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More from Merriam-Webster on perturb

Thesaurus: All synonyms and antonyms for perturb

Rhyming Dictionary: Words that rhyme with perturb

Spanish Central: Translation of perturb

Nglish: Translation of perturb for Spanish Speakers

Britannica English: Translation of perturb for Arabic Speakers

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to speed up the process or progress of

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