fluctuate
Americanverb (used without object)
-
to change continually; shift back and forth; vary irregularly.
The price of gold fluctuated wildly last month.
-
to move back and forth in waves.
- Synonyms:
- oscillate
verb (used with object)
verb
-
to change or cause to change position constantly; be or make unstable; waver or vary
-
(intr) to rise and fall like a wave; undulate
Usage
What does fluctuate mean? Fluctuate means to continually change or shift back and forth. The verb 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. This kind of continual change is called fluctuation. Example: The volume on my TV keeps fluctuating—it gets louder during commercials and then it gets quiet again when the show comes back on.
Related Words
See waver 1.
Other Word Forms
Etymology
Origin of fluctuate
First recorded in 1625–35; from Latin fluctuātus “undulated,” past participle of fluctuāre “to flow,” equivalent to fluctu(s) “a flowing” (derivative of fluere “to flow”) + -ātus -ate 1
Explanation
Something that fluctuates varies or changes — it's the opposite of steady. Like the ups and downs of the stock market or the relationship status of a Hollywood starlet. Fluctuate is a verb that describes movement, sometimes irregular, but often rising and falling in a wave-like pattern. The tides fluctuate according to the weather and season, for example. Your emotions fluctuate depending on what happens throughout the day, and so does your weight. In fact, you usually weigh less in the morning, before you've eaten. You're also taller, since your spine compresses as you walk around. So your height fluctuates, too.
Vocabulary lists containing fluctuate
Tier 2 Words for the SBAC ELA Items
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List 3
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Darius the Great Is Not Okay
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
"Our findings suggest that the regularity of bedtime, in particular, may be important for heart health. It reflects the rhythms of everyday life -- and how much they fluctuate," Nauha says.
From Science Daily • May 5, 2026
"Nuclear energy is essential in the energy mix," she said, arguing it provides stable electricity, unlike renewable sources such as wind and solar, whose output can fluctuate.
From Barron's • May 4, 2026
Winter rainfall helped replenish water supplies after 2025's dry summer but water stocks can fluctuate quickly with some river levels already starting to fall, raising concerns about what might happen in the months ahead.
From BBC • May 1, 2026
So for advisers and investors, monthly series offer refreshed 12-month protection at any time of the year, with a fixed level of downside protection, while the upside caps will fluctuate.
From MarketWatch • Apr. 28, 2026
Rick said, “A humanoid robot is like any other machine; it can fluctuate between being a benefit and a hazard very rapidly. As a benefit it’s not our problem.”
From "Do Androids Dream of Electric Sheep?" by Philip K. Dick
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
