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

• 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

If you hold a bond until maturity, you won’t be affected by this price fluctuation — you know you will receive the bond’s face value at maturity.

From MarketWatch • May 8, 2026

That makes them more susceptible to any localized economic downturn or currency fluctuation than a more geographically diverse fund, he says.

From The Wall Street Journal • Apr. 10, 2026

"By pushing and pulling on a phonon laser with light in the right way, we can reduce that phonon laser fluctuation significantly."

From Science Daily • Mar. 31, 2026

“The fluctuation in value during this time period is consistent with the entire crypto market, which is typical in a bear market,” company spokeswoman Victoria Davis told me by email.

From Los Angeles Times • Mar. 3, 2026

The slightest fluctuation in the weather outside my window, the smallest passing cloud, the changing position of the sun affected the mood of that room.

From "Hole in My Life" by Jack Gantos

Related Words

• variation