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

Diversifying supply chain partners can help stabilize costs and reduce reliance on any single market, protecting against price fluctuations and disruptions. —Reza Esmaeili, Forbes, 25 Mar. 2025

If nothing else, he’s already got a taste of the fluctuations of joy and despair every Ferrari driver comes to experience. —Luke Smith, The Athletic, 24 Mar. 2025

Unstable weather conditions, such as fluctuations in temperature and humidity and unexpected wind, often accompany rain. —Kamron Sanders, Better Homes & Gardens, 23 Mar. 2025

Heart palpitations Estrogen also helps regulate your heart rate and maintain healthy cholesterol levels, so fluctuations in the hormone can cause heart palpitations, even for women without a history of heart problems. —Erica Sweeney, SELF, 21 Mar. 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