fluctuate

verb

fluc·​tu·​ate ˈflək-chə-ˌwāt How to pronounce fluctuate (audio)
-chü-ˌāt
fluctuated; fluctuating

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
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 number of people crossing the Mexican border into Yuma County has fluctuated over the years. Juliana Kim, NPR, 24 Mar. 2024 Water levels fluctuate naturally in the Great Lakes from year-to-year. Caitlin Looby, Journal Sentinel, 21 Mar. 2024 In Buffett’s case, the cost of his security perks has fluctuated over the years between 2016 and 2023, averaging about $312,000. Amanda Gerut, Fortune, 21 Mar. 2024 Arlo Essential Wired Video Doorbell for $50 ($30 off) Amazon The runner-up in our Best Video Doorbells guide, this Arlo video doorbell fluctuates between $80 and $50 frequently. Louryn Strampe, WIRED, 20 Mar. 2024 Single-day and weekend passes are available, fluctuating from a minimum of $15 and upwards of $150. Marina Johnson, The Courier-Journal, 19 Mar. 2024 While a traditional clock might use a pendulum swinging back and forth to measure the passage of time, microwave oscillator clocks rely on electronic fields that fluctuate at frequencies of 300 MHz to 300 GHz. IEEE Spectrum, 19 Mar. 2024 While March saw an uptick in the number of trucks crossing, the UN has suggested that the volume of aid has been fluctuating. Nadeen Ebrahim, CNN, 18 Mar. 2024 Each year, the dates of Ramadan fluctuate, as its start is based on the phases of the moon. Marina Johnson, The Indianapolis Star, 8 Mar. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'fluctuate.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

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

First Known Use

1604, in the meaning defined at intransitive sense 2

Time Traveler
The first known use of fluctuate was in 1604

Dictionary Entries Near fluctuate

Cite this Entry

“Fluctuate.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fluctuate. Accessed 28 Mar. 2024.

Kids Definition

fluctuate

verb
fluc·​tu·​ate ˈflək-chə-ˌwāt How to pronounce fluctuate (audio)
fluctuated; fluctuating
1
: to move up and down or back and forth like a wave
2
: to be constantly changing especially up and down
fluctuation noun

More from Merriam-Webster on fluctuate

Last Updated: - Updated example sentences
Love words? Need even more definitions?

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