vac·​il·​late ˈva-sə-ˌlāt How to pronounce vacillate (audio)
vacillated; vacillating

intransitive verb

: to waver in mind, will, or feeling : hesitate in choice of opinions or courses
: to sway through lack of equilibrium
vacillatingly adverb
vacillator noun
Choose the Right Synonym for vacillate

hesitate, waver, vacillate, falter mean to show irresolution or uncertainty.

hesitate implies a pause before deciding or acting or choosing.

hesitated before answering the question

waver implies hesitation after seeming to decide and so connotes weakness or a retreat.

wavered in his support of the rebels

vacillate implies prolonged hesitation from inability to reach a firm decision.

vacillated until events were out of control

falter implies a wavering or stumbling and often connotes nervousness, lack of courage, or outright fear.

never once faltered during her testimony

Examples of vacillate in a Sentence

She has vacillated on this issue. vacillated for so long that someone else stepped in and made the decision
Recent Examples on the Web His commanding presence and ability to vacillate between one-liners and earnest remarks also reminded me a lot of the way Rivers conducted himself. Ben Bolch, Los Angeles Times, 7 June 2024 Kelly wildly vacillates between acting tough and acting a fool. Erin Qualey, Vulture, 8 May 2024 In taking these steps, Simon argues that Trump’s transactional deal-making exacerbated the chaotic nature of U.S. Middle East policy, which had vacillated between pieties about democracy promotion and realist visions of strategic dominance. Foreign Affairs, 18 Apr. 2023 But for the most part, the art form today vacillates between, on one hand, decrying social and/or personal injustices and, on the other, aiming at a kind of conspicuously literary self-portraiture. David Orr, New York Times, 18 Apr. 2024 See all Example Sentences for vacillate 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'vacillate.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


borrowed from Latin vacillātus, past participle of vacillāre "to be unsteady, totter, be weak or inconstant, waver," of uncertain origin

First Known Use

1597, in the meaning defined at sense 2a

Time Traveler
The first known use of vacillate was in 1597

Dictionary Entries Near vacillate

Cite this Entry

“Vacillate.” Dictionary, Merriam-Webster, Accessed 25 Jun. 2024.

Kids Definition


vac·​il·​late ˈvas-ə-ˌlāt How to pronounce vacillate (audio)
vacillated; vacillating
: to hesitate between courses or opinions : be unable to choose
vacillator noun

More from Merriam-Webster on vacillate

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!