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

Restoration actually improves income stability for workers by reducing vulnerability to lumber price fluctuations and disrupted operations, as endured during a 10-year moratorium triggered by protests and litigation. —Evan Mills, Mercury News, 15 Mar. 2026

The second will accept short-term fluctuations today in exchange for an income that grows over time with the economy. —Steve Booren, Denver Post, 15 Mar. 2026

Major Asian airlines, including Air India and Hong Kong’s Cathay Pacific, have almost doubled the fuel surcharge paid by passengers to account for fluctuations in energy prices. —Mithil Aggarwal, NBC news, 15 Mar. 2026

Despite the prevalence of readily available information on pricing and market fluctuations as well as details that make some watches stand out, everyone agreed the excitement around collecting is still alive and well. —Paige Reddinger, Robb Report, 13 Mar. 2026

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