Vacillate Meaning
/ˈvæ.sə.leɪt/Definition, CEFR level C2, pronunciation, examples, and quiz.
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Definition
verbTo waver between different opinions or actions; to be indecisive.
verbTo sway unsteadily from one side to the other; oscillate.
Sentence Examples
If you continue to vacillate, the opportunity will disappear.
Do not vacillate between options; make a firm decision.
CEFR Practice Quiz
She began to ____ between staying home or going out because she was uncertain.
CEFR Practice Quiz (Alternate)
Stop trying to ____ and make a firm decision.
Word Origin & History
From Latin vacillātum, supine form of vacillō (“sway, waver”). By surface analysis, Latin vacill- + -ate.
Literary Quotations & Historical Citations
"Its [the barometer's] normal register in the Paumotus [the Tuamotus] was 29.90, and it was quite customary to see it vacillate between 29.85 and 30.00, or even 30.05; […]"
— 1910, Jack London, The Heathen:
"Courageous, patriotic, yet vacillating, many of the noblest principles and the purest intentions, men of large possessions and ancient names, under the afflicting circumstances of the times, failed to render service to their unhappy country, but involved themselves in irremediable ruin."
— 1842, [anonymous collaborator of Letitia Elizabeth Landon], chapter XXIX, in Lady Anne Granard; or, Keeping up Appearances. […], volume II, London: Henry Colburn, […], →OCLC, page 68:
"Though it is vital to be alert for circumstances which require a change of plan, it is fatal to vacillate."
— 1944 October, I. A. Horowitz, “Readers' Games”, in Chess Review:
"On the streets of Berlin, Ruth and her compatriots vacillated "between hope and despair.""
— 2004, Chris Wallace, Character: Profiles in Presidential Courage:
"Oliveira couldn’t seem to decide if the point of his videos was to make a point about welfare — he vacillates between claiming Orthodox Jews are engaged in fraud and acknowledging they legitimately qualify for programs like Medicaid and food stamps that he doesn’t think taxes should pay for, at least when it comes to large Jewish families — or to hold up the Jewish communities in Kiryas Joel and Lakewood as models for white Americans."
— 2026 February 25, Arno Rosenfeld, “After Minneapolis, a YouTuber comes for Jewish ‘welfare queens’”, in The Forward, archived from the original on 27 Feb 2026:
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CEFR Practice Quiz
She began to ____ between staying home or going out because she was uncertain.
CEFR Practice Quiz (Alternate)
Stop trying to ____ and make a firm decision.