fluc·​tu·​ate | \ ˈflək-chə-ˌwāt How to pronounce fluctuate (audio) , -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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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

Let’s call it partly sunny for now, but cloud levels could fluctuate. Washington Post, "D.C.-area forecast: Warm but rather cloudy with a shower or two around through the weekend," 8 June 2019 SamKnows equipment is still collecting data for the project in 6,000 to 10,000 homes, Salter said, noting that the number fluctuates. Jon Brodkin, Ars Technica, "Ajit Pai isn’t saying whether ISPs deliver the broadband speeds you pay for," 19 Nov. 2018 There are about 28,000 American troops and civilian military personnel assigned to U.S. Forces Korea, although the number fluctuates during military exercises and when a new unit moves in to relieve another. Tom Vanden Brook, USA TODAY, "Pentagon bases about 28,000 U.S. troops in South Korea," 5 June 2018 Miami International Airport hosts 105 passenger and cargo airlines — the most of any U.S. airport — though that number fluctuates. Chabeli Herrera, miamiherald, "You can't fly Miami to Iceland nonstop anymore. But you can go to these new places," 31 May 2018 The numbers fluctuated some, ending the year at 330 million MAUs. Chris Morris, Fortune, "Twitter and the Trump Effect: Tracking the Mobile User Numbers," 25 Apr. 2018 Typically, coal is used to supply whatever power can’t be generated through these means, and because renewables like solar and wind can fluctuate, coal plants are often conscripted to meet goals. Avery Thompson, Popular Mechanics, "Britain Went an Entire Week Without Burning Coal," 10 May 2019 The city is planning on rolling out the fee before this year's peak tourist season, and the cost will fluctuate depending on the time of year. Chloe Foussianes, Town & Country, "The City of Venice Will Soon Start Charging Tourists an Entrance Fee," 4 Mar. 2019 Between 2011 and 2014, when the price of West Texas Intermediate — the benchmark price for domestic producers — fluctuated at or around $100 a barrel or more, California saw a modest rise in production. Rob Nikolewski, sandiegouniontribune.com, "California's ranking as an oil-producing state is slipping," 12 July 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

15 Jun 2019

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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 How to pronounce fluctuate (audio) \
fluctuated; fluctuating

Kids Definition of fluctuate

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

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Comments on fluctuate

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