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 of fluctuation

• oscillation
• change

Examples of fluctuation in a Sentence

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

Recent Examples on the Web

Wideband oscillations are rapid electrical fluctuations that can, in fact, destabilize renewable power systems. — Georgina Jedikovska, Interesting Engineering, 17 Sep. 2026

For women, the hormonal fluctuations of perimenopause and menopause can add another layer of brain fog, difficulty concentrating and trouble recalling words or information. — Lauryn Higgins, Flow Space, 16 Sep. 2026

Furthermore, energy cost fluctuations pass entirely to the end user. — Harvey Stober, CNBC, 15 Sep. 2026

About 82% of those homes are located in the Northeast, making that area particularly vulnerable to price fluctuations. — Mary Cunningham, CBS News, 15 Sep. 2026

Word History

First Known Use

15th century, in the meaning defined above

Rhymes for fluctuation

• ablation
• aeration
• bination
• carnation
• cassation
• castration
• causation
• centration
• cessation
• cetacean
• chelation
• citation

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