fluctuate
Americanverb (used without object)
-
fluctuates,
present (3rd person singular)
-
fluctuated,
past participle, past
-
fluctuating
present participle
-
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)
-
fluctuates,
present (3rd person singular)
-
fluctuated,
past participle, past
-
fluctuating
present participle
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.
Synonym Usage
See waver 1.
Other Word Forms
Derived Forms
Inflected Forms
Participles
Conjugated Forms
Present
-
fluctuatesimple
-
fluctuatessimple
-
have fluctuatedperfect
-
has fluctuatedperfect
-
am fluctuatingprogressive
-
are fluctuatingprogressive
-
is fluctuatingprogressive
-
have been fluctuatingperfect progressive
-
has been fluctuatingperfect progressive
Past
-
fluctuatedsimple
-
had fluctuatedperfect
-
was fluctuatingprogressive
-
were fluctuatingprogressive
-
had been fluctuatingperfect progressive
Future
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
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
List 3
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Darius the Great Is Not Okay
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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.
See Examples For:
However, the photons in each type of light fluctuate and interact in different ways.
From Science Daily ● Aug. 8, 2026
The secondary market allows fans to re-sell their tickets, potentially opening chances to see sold-through or popular sports, but the prices could fluctuate drastically.
From Los Angeles Times ● Aug. 7, 2026
She contacted BBC Your Voice to share her frustrations in watching holiday prices fluctuate.
From BBC ● Jul. 7, 2026
Giant defense contractors could benefit from DSRB-backed financing, say boosters, because government budgets often fluctuate annually, raising funding uncertainty that can increase borrowing costs.
From The Wall Street Journal ● Jul. 7, 2026
Some nearby examples, tens or hundreds of millions of light-years away, are powerful sources of X-rays, infrared radiation and radio waves, have extremely luminous cores and fluctuate in brightness on time scales of weeks.
From "Cosmos" by Carl Sagan
It’s one of the largest concentrations of capybaras in São Paulo, though its exact number of members fluctuates.
From Slate ● May 27, 2026
Joseph said that their annual spending fluctuates based on the work that needs to be done.
From The Wall Street Journal ● Apr. 5, 2026
If it fluctuates or you change jobs, this could affect how your earnings rise.
From BBC ● Feb. 17, 2026
The art conservator's income also fluctuates depending on the assignments she receives from institutions and individuals.
From Barron's ● Feb. 11, 2026
In addition, receptivity to innovation fluctuates in time within the same region.
From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond
Since then, global oil prices have fluctuated wildly.
From BBC ● Aug. 5, 2026
The figure was certainly made up: Over the following weeks it fluctuated up and down, ultimately settling at 57 — also made up.
From Los Angeles Times ● Jul. 29, 2026
For most of the past decade that gap fluctuated between $10 and $15 a barrel.
From MarketWatch ● Jul. 21, 2026
Asian equities fluctuated Tuesday following a tech-led sell-off on Wall Street as investors again questioned a long-running AI-fuelled boom, while crude largely held losses that came on the back of positive US-Iran talks.
From Barron's ● Jun. 23, 2026
Not only did variation and dip diverge from place to place, but in 1634 a group of English experimenters claimed that variation fluctuated over time.
From "The Invention of Science" by David Wootton
These adaptations evolved to optimize energy storage and usage in environments with fluctuating food availability.
From Science Daily ● Aug. 4, 2026
But fluctuating property taxes presented an additional financial challenge.
From MarketWatch ● Jul. 22, 2026
Affordability challenges, high material costs and fluctuating mortgage rates continue to pressure homebuilding.
From The Wall Street Journal ● Jul. 21, 2026
Markets usually frame questions in a yes-or-no fashion, with the price of a “contract” fluctuating between $0 and $1.
From Slate ● Jun. 30, 2026
I was out of the water, if only by a fluctuating two, three feet.
From "Life of Pi" by Yann Martel
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.
