fluctuation

American  

[fluhk-choo-ey-shuhn] / ˌflʌk tʃuˈeɪ ʃən /

noun

1. continual change from one point or condition to another.

2. wavelike motion; undulation.

3. Genetics. a body variation due to environmental factors and not inherited.

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fluctuation British  

/ ˌflʌktjʊˈeɪʃən /

noun

1. constant change; vacillation; instability

2. undulation

3. a variation in an animal or plant that is determined by environment rather than heredity

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Usage

What does fluctuation mean? Fluctuation is continual change. It’s a noun form of the verb fluctuate, meaning to continually change or shift back and forth. Fluctuation is most commonly used in the context of abstract or intangible things that frequently change, such as temperature, the stock market, or someone’s mood. Example: The fluctuation of the volume on my TV is really annoying—it gets louder during commercials and then it gets quiet again when the show comes back on.

Other Word Forms

Derived Forms

• nonfluctuation
  noun

Etymology

Origin of fluctuation

1400–50; late Middle English < Latin fluctuātiōn- (stem of fluctuātiō ) a fluctuation, wavering. See fluctuate, -ion

Explanation

The noun fluctuation refers to the deviations along the path from one point to another. We see frequent fluctuations in the stock market, as prices go up or down, and also in the weather, which is always changing. The original form of the word fluctuation appeared as a mid-15th-century French word derived from the Latin fluctuationem, meaning "vacillation." The verb stem fluctuāre meant "to undulate," referring to waves, giving rise to the idea of change and movement that is at the heart of the word. It might help to remember that fluctuation has the same root as the word fluent, and to think of it as something flowing, with frequent change along the way.

Example Sentences

This 16% fluctuation then is pretty dramatic, but it’s not a one-off.

From MarketWatch • Jun. 9, 2026

According to Margolis, the smaller trim size was previously the industry standard for U.S.-based publishing houses, and any fluctuation is due to the evolution of printing technology.

From Los Angeles Times • May 27, 2026

Benjamin Boisson, a fruit grower in southern France, said worried the extreme fluctuation in temperature would cause a sharp drop in production, as well as complicate storage.

From Barron's • May 26, 2026

That’s nearly triple its average daily fluctuation over the previous five years.

From The Wall Street Journal • Apr. 17, 2026

Perhaps the universe is just a quantum fluctuation on a grand scale—an enormous singular particle that came into existence out of the ultimate vacuum.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife

Related Words

• variation