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

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 Affected vehicles may display a malfunction indicator light or maybe just a fluctuating fuel gauge. Jonathan M. Gitlin, Ars Technica, "Ford recalls 1.5 million Focuses for faulty fuel tank purge valves," 25 Oct. 2018 In part, these fees are a byproduct of a fluctuating airfare market: Though prices may change based on new route competition or the time of year, airlines can count on the prices of the fees staying stable. Meredith Carey, Condé Nast Traveler, "These Airlines Made the Most on Extra Fees Last Year," 19 Sep. 2018 Clarkson has been in and out of headlines over the past few years due to her fluctuating weight. Connor Whittum, Billboard, "Kelly Clarkson Reveals Thyroid Issue & Discusses 37-Pound Weight Loss on 'Today'," 8 June 2018 The Grammy-winning singer has been the talk of much chatter over the years about her fluctuating weight. Lisa Respers France, CNN, "Kelly Clarkson reveals 'secret' to her weight loss," 23 May 2018 Bacon’s minutes fluctuated last season, but Clifford repeatedly said Bacon could end up an NBA starter. Rick Bonnell, charlotteobserver, "Why Charlotte Hornets' new coaching staff likes a big slice of Dwayne Bacon," 3 July 2018 The Yankees, essentially, timed the fluctuating market of public sentiment involving Chapman’s domestic violence to maximize their profit. Will Leitch, Daily Intelligencer, "The Sports World Needs Its #MeToo Moment," 27 June 2018 The results, published in Monday’s issue of the Proceedings of the National Academy of Sciences, show a fluctuating line whose peaks and troughs correspond to salient events in Roman history. New York Times, "An Ice Core Reveals the Economic Health of the Roman Empire," 14 May 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

16 Nov 2018

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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Comments on fluctuate

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


living or existing for a long time

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