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
- nonfluctuating adjective
- unfluctuating adjective
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.
Your return on investment may be worth it in the first few years, but it may fluctuate over time as your children go to school.
From MarketWatch • Apr. 10, 2026
The renewed attention around his career comes at a time when conversations about labor, dignity, and public perception remain ongoing, particularly in industries where visibility can fluctuate dramatically.
From Salon • Apr. 4, 2026
"Dragon fruit has helped me diversify the farm income. If coffee prices fall or pepper prices fluctuate, crops like dragon fruit helped me sustain the estate," he says.
From BBC • Mar. 26, 2026
To be sure, oil prices can fluctuate wildly in times of uncertainty.
From Los Angeles Times • Mar. 10, 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
![]()
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.