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

• 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

Burnley has experienced significant fluctuations in recent years, having been promoted to the Premier League in 2009, 2014, 2016, 2023, and again before the start of this season. —Ben Verbrugge, MSNBC Newsweek, 16 Aug. 2025

Firms in finance and real estate are more sensitive to financial market fluctuations than to tariff policy. —William Dunkelberg, Forbes.com, 15 Aug. 2025

The Census surveys 60,000 households every month for the Current Population Survey, which tracks fluctuations in population. —Lauren Villagran, USA Today, 13 Aug. 2025

Other tricks the group employed included spraying women’s hairspray on the vault’s heat detectors to temporarily insulate them from sensing the room’s fluctuations in temperature. —Yasmeen Hamadeh, People.com, 10 Aug. 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