Definition of vacillatenext

Synonym Chooser

How does the verb vacillate differ from other similar words?

Some common synonyms of vacillate are falter, hesitate, and waver. While all these words mean "to show irresolution or uncertainty," vacillate implies prolonged hesitation from inability to reach a firm decision.

vacillated until events were out of control

When is it sensible to use falter instead of vacillate?

While the synonyms falter and vacillate are close in meaning, falter implies a wavering or stumbling and often connotes nervousness, lack of courage, or outright fear.

never once faltered during her testimony

When would hesitate be a good substitute for vacillate?

The words hesitate and vacillate are synonyms, but do differ in nuance. Specifically, hesitate implies a pause before deciding or acting or choosing.

hesitated before answering the question

When could waver be used to replace vacillate?

Although the words waver and vacillate have much in common, waver implies hesitation after seeming to decide and so connotes weakness or a retreat.

wavered in his support of the rebels

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of vacillate Yet Brown, who has vacillated on virtually everything this season, has gone in a different direction. Kristian Winfield, New York Daily News, 1 Apr. 2026 Trump has been more active than ever on social media in his second term, including posting lengthy all-caps screeds offering vacillating updates on the war. Alexander Smith, NBC news, 30 Mar. 2026 Trump has vacillated between indifference and contempt for the USMCA, at times threatening to pull out of the agreement altogether and work instead to negotiate two separate, bilateral deals with Mexico and Canada. Kate Nishimura, Sourcing Journal, 18 Mar. 2026 Watch a season of the Y2K reality juggernaut and the tone will vacillate wildly between cringe-worthy put-downs via Janice Dickinson, cringier photoshoots, feel-good runway lessons with Miss J, and body positivity monologues from Tyra Banks. Madeline Hirsch, InStyle, 17 Feb. 2026 See All Example Sentences for vacillate
Recent Examples of Synonyms for vacillate
Verb
  • And the Los Angeles Chargers didn’t hesitate on pulling the trigger.
    Greg Dudek, Boston Herald, 15 May 2026
  • When leadership is too removed, teams hesitate.
    Sue Mysko, Forbes.com, 15 May 2026
Verb
  • One risk is that the AI might falter and fail to detect that a person has an actual mental health condition that warrants attention.
    Lance Eliot, Forbes.com, 16 May 2026
  • With most tropical reefs expected to face conditions like the Gulf’s by 2100—and already faltering under increasingly frequent marine heat waves—that makes the Gulf’s coral a source of valuable genetic information about resilience that could have implications for the rest of the world’s reefs.
    Meghan Bartels, Scientific American, 14 May 2026

Browse Nearby Words

Cite this Entry

“Vacillate.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/vacillate. Accessed 18 May. 2026.

More from Merriam-Webster on vacillate

Love words? Need even more definitions?

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

More from Merriam-Webster