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
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vacillatesimple
-
vacillatessimple
-
have vacillatedperfect
-
has vacillatedperfect
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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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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
His commanding presence and ability to vacillate between one-liners and earnest remarks also reminded me a lot of the way Rivers conducted himself.
From Los Angeles Times ● Jun. 7, 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
Fuhrman, who was 12 when Orphan premiered, was lauded for her ability to vacillate between Esther’s precocious ersatz child and deranged killer modes.
From The Verge ● Jan. 26, 2022
The Obayifo’s shifty eyes vacillate between me and Ama.
From "Kwame Crashes the Underworld" by Craig Kofi Farmer
Once he settles on the sofa beside me, McKellen vacillates between performative storytelling and genuine reflection.
From Los Angeles Times ● Apr. 8, 2026
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
She vacillates between optimism and despair over Iran’s future.
From Washington Post ● Apr. 24, 2023
But knowledge is changeable, and often vacillates between truth and error, yet, as a rule, is rectified more and more in the course of life, though certainly in very different degrees.
From The World As Will And Idea (Vol. 1 of 3) by Arthur Schopenhauer
Over the next few seconds, the crew vacillated between slowing the aircraft and picking up speed to redo the landing, according to details about the flight released this week by the National Transportation Safety Board.
From The Wall Street Journal ● Sep. 10, 2026
Ellison and his executives have vacillated from anger to acceptance.
From Los Angeles Times ● Aug. 12, 2026
His children, Kelly and Jack, vacillated between showering him with affection and berating him for not catering to their whims.
From Salon ● Jul. 24, 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 love for him vacillated from one entry to another.
From "Americanized" by Sara Saedi
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
The arrival of the Iamaleava brothers prompted quarterbacks Joey Aguilar and Robert McDaniel to enter the transfer portal, with Demaricus Davis vacillating on his future, according to Foster.
From Los Angeles Times ● Apr. 27, 2025
Oppenheimer modulates the lighting during the scenes from cool to warm and back again, underlining the vacillating feelings they can’t acknowledge outright.
From New York Times ● Dec. 5, 2024
Three overlapping reasons appear to have converged in Adams’s mind and provided decisive direction to a foreign policy that, until then, had been vacillating between the incompatible agendas of the Federalists and the Republicans.
From "Founding Brothers: The Revolutionary Generation" by Joseph J. Ellis
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Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
