fluctuation

noun

fluc·​tu·​a·​tion ˌflək-chə-ˈwā-shən 

-chü-ˈā-

plural fluctuations

: an act or instance of fluctuating : an irregular shifting back and forth or up and down in the level, strength, or value of something

Small fluctuations in prices are to be expected.

Some fluctuation in real estate values is not unusual.

North American species in general, having contended with blazing July days and frosty September nights as they evolved, are much more tolerant of temperature fluctuations than tropical species are.

—Jonathan Franzen

fluctuational

ˌflək-chə-ˈwā-sh(ə-)nəl 

-chü-ˈā-

adjective

Synonyms

• change
• flux
• inconstancy
• oscillation

Examples of fluctuation in a Sentence

political instability that resulted in wild fluctuations in the overseas stock markets

Recent Examples on the Web

While last week's stock market selloff took its toll on the fortune of the world's richest, one man has been largely able to weather the fluctuations brought on by the Trump administration's trade policies. —John W. Dean, MSNBC Newsweek, 7 Apr. 2025

But by translating these fluctuations in brightness into fluctuations in acoustic frequencies, scientists can tune in to a star’s sound, learning important information about its age and its other traits. —Sam Walters, Discover Magazine, 2 Apr. 2025

The executives compensation packages include stock options, the full value of which might never be realized due to fluctuations in stock prices and vesting schedules. —David Moin, Footwear News, 2 Apr. 2025

Karoline Leavitt on Tuesday was asked what Trump has to say to Americans who rely on their retirement accounts and have concerns about the fluctuations in the stock market. —Brian Bennett, Time, 1 Apr. 2025

Word History

First Known Use

15th century, in the meaning defined above

Rhymes for fluctuation

• abdication
• aberration
• abjuration
• abnegation
• abrogation
• acceptation
• acclamation
• acclimation
• accusation
• activation
• actuation
• acylation

Medical Definition

fluctuation

noun

fluc·​tu·​a·​tion ˌflək-chə-ˈwā-shən 

1

: a motion like that of waves

especially : the wavelike motion of a fluid collected in a natural or artificial cavity of the body observed by palpation or percussion

2

a

: a slight and nonheritable variation

especially : such a variation occurring in response to environmental factors

b

: recurrent and often more or less cyclic alteration (as of form, size, or color of a bodily part)

fluctuate

ˈflək-chə-ˌwāt 

verb

fluctuated; fluctuating