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

Subscription services such as Apple Music and Apple TV for media, Apple Arcade for gaming, and Apple Fitness Plus offer benefits to consumers and predictable revenue for Apple, compared with the fluctuations in hardware costs. — Ewan Spence, Forbes.com, 15 Aug. 2026

Unlike other meat products, the cost of chicken has seen little fluctuation in recent months, so much so that July’s 3-cent drop signaled the single biggest monthly change dating back to November 2024. — Claire Malon, Chicago Tribune, 14 Aug. 2026

Back in the early 1980s, amid a volatile chicken market, McDonald’s needed help pricing their nuggets and limiting the risk of menu price fluctuations. — Sarah Glodek, Fortune, 14 Aug. 2026

Astronomers have long known that Betelgeuse has an unexplained six-year-long periodic fluctuation in its brightness in addition to its less dramatic 400-day cycle. — Phil Plait, Scientific American, 14 Aug. 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