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

Keep scrolling for more

Synonyms & Antonyms for fluctuate



Visit the Thesaurus for More 

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 The Arctic is also characterized by an ice cover that fluctuates with the seasons. National Geographic, "Penguins don't live at the South Pole, and more polar myths debunked," 3 Feb. 2020 He additionally mostly put away the drop shot, which fluctuated in its success rate. Ravi Ubha, CNN, "Novak Djokovic rallies to win his eighth Australian Open title after beating Dominic Thiem in tense final," 2 Feb. 2020 Turnout, which has fluctuated widely in recent elections, will also have a major impact on the final outcome. William Cummings, USA TODAY, "'Be prepared for anything': Klobuchar surge could turn Iowa caucuses into 5-way race, Monmouth poll finds," 29 Jan. 2020 The simplest explanation for the correlations traces them to pairs of quantum particles that fluctuated into existence as space exponentially expanded at the start of the Big Bang. Quanta Magazine, "Cosmic Triangles Open a Window to the Origin of Time," 29 Oct. 2019 These batteries are increasingly used to store power from sources that fluctuate, such as solar and wind energy. Ben Guarino, Washington Post, "Nobel Prize in chemistry awarded for rechargeable lithium-ion batteries," 9 Oct. 2019 As of August, a company must have an unadjusted market cap of at least $8.2 billion (a number that fluctuates based on the stock market’s booms and busts). Matthew De Silva, Quartz, "The art and science of stewarding the S&P 500," 25 Sep. 2019 In-city producers pay a $150 base tax per well, a $30 annual oil well permit fee per producing well and a per-barrel fee that fluctuates based on the producer price index for crude oil, but would never drop below 12.5 cents a barrel. Daily Pilot, "Does oil company owe city of Seal Beach $9 million or more? City officials are drilling for answers," 20 Sep. 2019 But a quantum mechanical particle in a trap of some sort will have a position and motion that are constantly fluctuating. David Grossman, Popular Mechanics, "Looks Like We Have a New Material State," 5 Sep. 2019

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.

See More

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

Keep scrolling for more

Learn More about fluctuate

Time Traveler for fluctuate

Time Traveler

The first known use of fluctuate was in 1604

See more words from the same year

Statistics for fluctuate

Last Updated

23 Feb 2020

Cite this Entry

“Fluctuate.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fluctuates. Accessed 24 Feb. 2020.

Keep scrolling for more

More Definitions for fluctuate


How to pronounce fluctuate (audio)

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.

Keep scrolling for more

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).


See Definitions and Examples »

Get Word of the Day daily email!

Test Your Vocabulary

More Confusing Words—Quiz

  • cats on impossible timber
  • The magician ______ moved the selected card to the top of the deck.
Spell It

Can you spell these 10 commonly misspelled words?


Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!