per·​turb | \pər-ˈtərb \
perturbed; perturbing; perturbs

Definition of perturb 

transitive verb

1 : to cause to be worried or upset : disquiet

2 : to throw into confusion : disorder

3 : to cause to experience a perturbation

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Other Words from perturb

perturbable \ pər-​ˈtər-​bə-​bəl \ 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

Despite Evertonians becoming increasingly perturbed at Allardyce's defensive tactics, the 63-year-old opted to shift the blame game from his own misgivings and claim that his senior stars weren't showing their best form or their talents., "Sam Allardyce Risks Alienating Everton Stars Over 'No Value for Money' Claims," 27 Feb. 2018 But privacy groups are perturbed by drone monitoring—already used elsewhere in searches and surveillance. Gregory Barber, WIRED, "Crime Fighting Gets High-Tech Advances," 3 June 2018 Largely, however, health care companies—and drug makers specifically—don’t seem particularly perturbed by the tough talk. Sy Mukherjee, Fortune, "Brainstorm Health: Trump Drug Price Prediction, Sanofi's Roseanne Subtweet, Healthy Life Expectancy," 30 May 2018 In contrast, majority-level concerns about China’s military power or Russia’s territorial ambitions were limited to Republican leaders (the greater Republican-leaning public did not seem to be especially perturbed by China or Russia). Adam Taylor, Washington Post, "The Pentagon says China and Russia are bigger problems for U.S. than terrorists. American voters may not agree.," 20 Jan. 2018 Fans more recently acquainted with the book or with the 1994 movie might be perturbed by the slight changes, but going in cold is preferable. Kelly Lawler, USA TODAY, "Review: PBS's 'Little Women' is a warm bath of lightness and love," 11 May 2018 In Hawaiian myth and culture, Pele is the goddess of fire and volcano and devours the Big Island when she is perturbed. Angela Fritz,, "8 facts about Hawaii's Kilauea volcano," 7 May 2018 The distance between them would decrease the chance that environmental effects could perturb both particles at once, which potentially makes such qubits highly stable, says study co-lead author Hao Zhang, a quantum physicist at Delft. Charles Q. Choi, Scientific American, "Quantum Leaps in Quantum Computing?," 1 Dec. 2017 But this moisture also perturbs air currents, so in some years, Pacific moisture is all channeled toward California via atmospheric rivers while in other years, this concentrated plume discharges elsewhere, leaving the Golden State to dry out. Umair Irfan, Vox, "California’s droughts and deluges portend the weather “whiplash” to come," 24 Apr. 2018

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

23 Sep 2018

Look-up Popularity

Time Traveler for perturb

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

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More Definitions for perturb



English Language Learners Definition of perturb

: to cause (someone) to be worried or upset


per·​turb | \pər-ˈtərb \
perturbed; perturbing

Kids Definition of perturb

: to disturb in mind : trouble greatly

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Comments on perturb

What made you want to look up perturb? Please tell us where you read or heard it (including the quote, if possible).


playful or foolish behavior

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