- present participle of vacillate.
vacillating
Americanadjective
-
not resolute; wavering; indecisive; hesitating.
an ineffectual, vacillating person.
- Synonyms:
- irresolute, hesitant
-
oscillating; swaying; fluctuating.
a vacillating indicator.
adjective
Synonym Usage
See fickle.
Other Word Forms
Etymology
Origin of vacillating
First recorded in 1805–15; vacillat(e) + -ing 2
Explanation
If someone can't make up their mind, you can call that person vacillating. A vacillating student might not know whether to commit to a major in electrical engineering or in art history. The word vacillating comes from the Latin vacillat- meaning "swayed." When you're having trouble sticking to a decision, you can be described as vacillating — meaning that you are swaying between two choices. The spelling of vacillating can be tricky to remember. But vacillating, like its definition "uncertain," has the letter c in it. And to remember the two ls, think about the word's meaning, wavering between two choices.
Vocabulary lists containing vacillating
Frankenstein
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Dr. Martin Luther King Jr.'s "I've Been to the Mountaintop" (1968)
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The Importance of Being Earnest
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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.
The film has wavered too much, and the story’s vacillating opinion on devices starts to point back at Disney.
From Salon ● Jun. 21, 2026
They pose the theory that the stock market is vacillating between thematic momentum and macro conditions.
From MarketWatch ● Jun. 15, 2026
Whereas “The Homecoming” was noted for its claustrophobic machismo, here it’s the women who dominate the proceedings, vacillating between sisterly tenderness and bitter recriminations.
From New York Times ● Feb. 9, 2024
We hate vacillating on matters of major consequence.
From Seattle Times ● Jan. 14, 2024
Aliya’s face is flustered, vacillating between concern and disbelief.
From "Saints and Misfits" by S.K. Ali
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.
