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

The department cleared about 38% of violent crimes in 2018 and about 47% in 2024, with several fluctuations within that range in the years between, according to state data. —Hailey Wang, Los Angeles Times, 9 May 2026

Valeska Zambra, a PhD student and lead author of the study, said the team aimed to determine whether the magnetic fluctuations inside the material could explain the high-field superconductivity. —Georgina Jedikovska, Interesting Engineering, 8 May 2026

Again, both venues and others around the globe operate on a system of price fluctuation based on demand. —New Atlas, 8 May 2026

Originally invented by Swiss engineer Jean-Léon Reutter in 1928, the Atmos operates using tiny fluctuations in air temperature. —Taylor Stoddard, Robb Report, 8 May 2026

Word History

First Known Use

15th century, in the meaning defined above

Rhymes for fluctuation

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

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