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

Some of the symptoms include fatigue, brain fog, joint and muscle pains, weight fluctuations, depression, anxiety and hair loss. —Michelle Lee, People.com, 11 July 2025

Rising food and labor costs, staffing shortages, and commercial rent fluctuations continue to affect long-term sustainability in the hospitality industry. —Nia Bowers, USA Today, 10 July 2025

Atomic clocks can detect fluctuations of just a few milliseconds in the length of a day. —Daisy Dobrijevic, Space.com, 10 July 2025

Costco announced late Wednesday that its U.S. core comparable sales, excluding gas prices and currency fluctuations, rose 5.5% for the four weeks ending Jul. 6, slightly below Wall Street’s estimate of 6% estimate but above buy-side expectations of 5%, according to JPMorgan’s analysis. —Paulina Likos, CNBC, 10 July 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