vacillate
Americanverb (used without object)
-
vacillates,
present (3rd person singular)
-
vacillated,
past participle, past
-
vacillating
present participle
verb
-
to fluctuate in one's opinions; be indecisive
-
to sway from side to side physically; totter or waver
Synonym Usage
See waver 1.
Other Word Forms
Derived Forms
Inflected Forms
Participles
Conjugated Forms
Present
-
vacillatesimple
-
vacillatessimple
-
have vacillatedperfect
-
has vacillatedperfect
-
am vacillatingprogressive
-
are vacillatingprogressive
-
is vacillatingprogressive
-
have been vacillatingperfect progressive
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has been vacillatingperfect progressive
Past
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vacillatedsimple
-
had vacillatedperfect
-
was vacillatingprogressive
-
were vacillatingprogressive
-
had been vacillatingperfect progressive
Future
Etymology
Origin of vacillate
First recorded in 1590–1600; from Latin vacillātus (past participle of vacillāre “to sway to and fro”); see -ate 1
Explanation
Vacillate means to waver back and forth, unable to decide. You might vacillate between ordering waffles and pancakes at your favorite diner — it’s hard to pick just one when both are so tasty! Something that vacillates sways or fluctuates, often quite unsteadily. So use this verb to describe the staggering motions of a person who has had too much to drink, as well as the opinions of someone who can’t make up her mind. Synonyms include vibrate, hesitate, and waver. A wise Ethiopian proverb advises, "Do not vacillate or you will be left in between doing something, having something, and being nothing.”
Vocabulary lists containing vacillate
Grade 12, List 5
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100 SAT Words Beginning with "V"
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Long Walk to Freedom
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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.
See Examples For:
The studio spectators cut him off with a loud, extended chorus of boos, as Colbert appeared to vacillate between laughing and choking up.
From Slate ● Jul. 18, 2025
You have to see it so many times because you have to vacillate between watching the show and watching the audience.
From Los Angeles Times ● Oct. 13, 2024
His leadership skills were lackluster, he was not a charismatic or inspiring speaker, he tended to vacillate in decision-making and he struggled to retain the best staffers.
From Salon ● Jul. 24, 2022
The film embraces the idea that identity is dynamic and can vacillate wildly over time.
From New York Times ● Feb. 4, 2022
The Obayifo’s shifty eyes vacillate between me and Ama.
From "Kwame Crashes the Underworld" by Craig Kofi Farmer
It is closer to music than epic, a mesmerizing suite of songs that conveys Tennyson’s private sorrow as he vacillates from unbearable agony to precarious hope.
From The Wall Street Journal ● Feb. 20, 2026
When the conspiracy at the center of “The Chair Company” consumes the life of Ron Trosper, he vacillates between screaming fury and the type of validation that lights up his smile from the inside.
From Salon ● Oct. 13, 2025
As the score vacillates between rhythmic, melodic passages and warped dissonance, they look at times like they’re trying to worm their way out of their bodies.
From New York Times ● Apr. 24, 2023
But it wouldn’t be a reach to believe the NBA legend’s criticism of his portrayal in the show — as a tempestuous and profane malcontent who vacillates between anger and despair — helped boost ratings.
From Washington Post ● May 15, 2022
He vacillates abominably and forever between two irreconcilable desires.
From A Book of Prefaces by H. L. (Henry Louis) Mencken
Ellison and his executives have vacillated from anger to acceptance.
From Los Angeles Times ● Aug. 12, 2026
Both sides have vacillated between tough talk and de-escalation in recent days, but the rhetoric took a harder turn on Tuesday.
From The Wall Street Journal ● Oct. 15, 2025
Her parents vacillated between wanting to take a hard line and accommodating Olivia’s apparent limitations for the sake of ease.
From Slate ● Jan. 4, 2025
My emotions vacillated from fury to giddiness to crushing depression on an hourly basis.
From Salon ● Nov. 5, 2023
She and Bunny had a relationship the likes of which I had seldom seen except in couples married for twenty years or more, a relationship which vacillated between the touching and the annoying.
From "The Secret History" by Donna Tartt
They pose the theory that the stock market is vacillating between thematic momentum and macro conditions.
From MarketWatch ● Jun. 15, 2026
We are a country, and a world, chasing its tail – vacillating between hatred, anger and a desire for peace.
From Salon ● Sep. 19, 2024
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
After a wildly vacillating game against Marquette in which the Bruins’ 12-point lead became a seven-point deficit, they had the ball trailing by two with 21 seconds left.
From Los Angeles Times ● Nov. 21, 2023
I had been vacillating during the last month between Bruce Wayne and Peter Parker.
From "Twilight" by Stephenie Meyer
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.
