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
-
has been vacillatingperfect progressive
Past
-
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:
A towering outside hitter, he was known for his ability to vacillate between power and finesse.
From Los Angeles Times ● Aug. 28, 2025
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 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
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
Meanwhile, Merritt vacillates between despair at the prospect of her eviction and elation when she dreams of returning to Poplar Boulevard.
From Los Angeles Times ● Jun. 3, 2024
When he isn’t mugging for Reed’s camera he vacillates between a stony-faced refusal to admit guilt and an approximation of remorse.
From Salon ● Mar. 26, 2024
“He vacillates between being very intense and focused about his work and just really silly and fun,” Diarra Kilpatrick, who plays Paul’s wife, Clara, said in a video interview.
From New York Times ● Mar. 2, 2023
Is it to be wondered at, if many a modern mother, in this predicament, vacillates between the two?
From Heart and Soul by Maveric Post by Victor Mapes
Instead, I vacillated between forgetting all about cancer some days and feeling like death was imminent others, and it was hard to predict what would prompt either extreme.
From Slate ● May 6, 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
“He was begging to be able to do something on the offensive side,” Skipper said of the redshirt junior, who has vacillated between the offensive and defensive lines during his seven seasons with the team.
From Los Angeles Times ● Oct. 13, 2025
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
My love for him vacillated from one entry to another.
From "Americanized" by Sara Saedi
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
But Cohen also said he was “compelled to comment upon the vacillating positions of the City of Atlanta throughout this litigation.”
From Seattle Times ● Sep. 13, 2023
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.
