fluc·​tu·​ate | \ ˈflək-chə-ˌwāt, -chü-ˌāt\
fluctuated; fluctuating

Definition of fluctuate

intransitive verb

1 : to shift back and forth uncertainly Oil prices fluctuated. Temperatures fluctuated.
2 : to rise and fall in or as if in waves The boat fluctuated on the rough sea.

transitive verb

: to cause to fluctuate

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Other Words from fluctuate

fluctuation \ ˌflək-​chə-​ˈwā-​shən , -​chü-​ˈā-​ \ noun
fluctuational \ ˌflək-​chə-​ˈwā-​shnəl , -​shə-​nᵊl, -​chü-​ˈā-​ \ adjective

Synonyms & Antonyms for fluctuate


change, mutate, shift, snap, vary


plateau, stabilize

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Choose the Right Synonym for fluctuate

swing, sway, oscillate, vibrate, fluctuate, waver, undulate mean to move from one direction to its opposite. swing implies a movement of something attached at one end or one side. the door suddenly swung open sway implies a slow swinging or teetering movement. trees swaying in the breeze oscillate stresses a usually regular alternation of direction. an oscillating fan vibrate suggests the rapid oscillation of an elastic body under stress or impact. the vibrating strings of a piano fluctuate suggests constant irregular changes of level, intensity, or value. fluctuating interest rates waver stresses irregular motion suggestive of reeling or tottering. the exhausted runner wavered before collapsing undulate suggests a gentle wavelike motion. an undulating sea of grass

Examples of fluctuate in a Sentence

His popularity has fluctuated during his term in office. In the desert, the temperature fluctuates dramatically.

Recent Examples on the Web

Who's Filing The number of new people who file for unemployment benefits fluctuates from week to week, but the four-week average has been moving downward since the most recent recession ended. Eric Morath, WSJ, "U.S. Jobless Claims Edged Lower Last Week," 8 Nov. 2018 Photographer: David Williams/Bloomberg Buffett has said operating results are a better barometer of company performance, in part because Berkshire’s more than $170 billion stock portfolio can fluctuate from quarter to quarter. Philip Brian Tabuas, Bloomberg.com, "Behind the Scenes at the Annual Berkshire Meeting in Omaha," 5 May 2018 Females typically take three years or longer between pregnancies, so births can fluctuate from year to year. CBS News, "Endangered right whales, on brink of extinction, could be facing "beginning of the end"," 27 Mar. 2018 Unlike other cryptocurrencies that fluctuate wildly in value, one tether generally equals one dollar. Steven Russolillo, WSJ, "The Mystery Behind Tether, the Crypto World’s Digital Dollar," 12 Aug. 2018 Just as important though was the play of a defensive midfield that fluctuated personnel and roles. Edward Lee, baltimoresun.com, "Review & preview: Goucher men’s lacrosse," 20 June 2018 Bitcoin is not a currency, because a currency is supposed to be a stable store of value, and a currency that can fluctuate 25% in a day can’t be used, for instance, to pay wages, because the wages could drop by 25% in a day. Jen Wieczner, Fortune, "Billionaire George Soros Is Using Blockchain Technology to Help Migrants," 25 Jan. 2018 But as the flows have fluctuated in recent years, the causes have become more elusive. Alicia A. Caldwell, WSJ, "As Migration From Guatemala Surges, U.S. Officials Seek Answers," 13 Oct. 2018 That's no shade to Alessia or Chance, but a comment on the ever-fluctuating rationales of award shows. Allie Gemmill, Teen Vogue, "BTS Is Ineligible for a Best New Artist Grammy and Fans Have Jokes," 2 Nov. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'fluctuate.' 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 fluctuate

1604, in the meaning defined at intransitive sense 2

History and Etymology for fluctuate

Latin fluctuatus, past participle of fluctuare, from fluctus flow, wave, from fluere — more at fluid

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Statistics for fluctuate

Last Updated

12 Jan 2019

Look-up Popularity

Time Traveler for fluctuate

The first known use of fluctuate was in 1604

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More Definitions for fluctuate



English Language Learners Definition of fluctuate

: to change level, strength, or value frequently


fluc·​tu·​ate | \ ˈflək-chə-ˌwāt \
fluctuated; fluctuating

Kids Definition of fluctuate

: to change continually and especially up and down The temperature fluctuated.

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