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

Definition of vacillate

intransitive verb

1 : to waver in mind, will, or feeling : hesitate in choice of opinions or courses
2a : to sway through lack of equilibrium

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Other Words from vacillate

vacillatingly \ ˈva-​sə-​ˌlā-​tiŋ-​lē How to pronounce vacillatingly (audio) \ adverb
vacillator \ ˈva-​sə-​ˌlā-​tər How to pronounce vacillator (audio) \ 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 The Dolphins vacillated between second-year quarterback Josh Rosen and Fitzpatrick last season, and won three of their last six games with Fitzpatrick at the helm. cleveland, "Browns’ Kevin Stefanski on Chad O’Shea, his new WR coach & passing game coordinator: ‘He has a unique knowledge of a successful program’," 4 Feb. 2020 Behind all of this vacillating lies a 21st-century reality: There has been a structural shift in American interests in the Middle East, one that Washington is having a hard time acknowledging. Martin Indyk, WSJ, "The Middle East Isn’t Worth It Anymore," 17 Jan. 2020 Even more encouraging for a Denver offense that had vacillated between stagnant and wayward, every one of their first half 3-pointers was created off an assist. Mike Singer, The Denver Post, "Nuggets pound Knicks, snap two-game losing streak behind season-high 21 three-pointers," 5 Dec. 2019 Biden’s team has, for months, vacillated between the best message for the candidate. Time, "Joe Biden Refocuses on White, Working-Class Voters," 23 Oct. 2019 Kasie, meanwhile, searches for something resembling romance, vacillating between the transactional affection of a clothing tycoon (Ronnie Kim) and the tender attention of a parking valet (Octavio Pizano). New York Times, "The Week in Arts: A Mini-Festival of Music and a 9/11 Remembrance," 7 Sep. 2019 Some say its electrons may be rapidly vacillating between insulating and conducting states in some novel quantum fashion. Quanta Magazine, "Paradoxical Crystal Baffles Physicists," 2 July 2015 The mood among participants vacillated greatly throughout the day. Eric Heisig, cleveland, "Massive opioid settlement talks in Cleveland stall as first federal trial looms," 18 Oct. 2019 Kamala Harris vacillated between her strong first debate performance (when addressing Trump) and her weak second performance. NBC News, "Status quo remains intact after third Democratic debate," 13 Sep. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'vacillate.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of vacillate

1597, in the meaning defined at sense 2a

History and Etymology for vacillate

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

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Time Traveler for vacillate

Time Traveler

The first known use of vacillate was in 1597

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Statistics for vacillate

Last Updated

9 Feb 2020

Cite this Entry

“Vacillate.” Dictionary, Merriam-Webster, Accessed 18 Feb. 2020.

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More Definitions for vacillate


How to pronounce vacillate (audio)

English Language Learners Definition of vacillate

formal : to repeatedly change your opinions or desires


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

Kids Definition of vacillate

: to hesitate between courses or opinions : be unable to choose

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