vacillate

verb

vac·​il·​late ˈva-sə-ˌlāt 

vacillated; vacillating

intransitive verb

1

: to waver in mind, will, or feeling : hesitate in choice of opinions or courses

2

a

: to sway through lack of equilibrium

b

: fluctuate, oscillate

vacillatingly

ˈva-sə-ˌlā-tiŋ-lē 

adverb

vacillator

ˈva-sə-ˌlā-tər 

noun

Synonyms

• balance
• dither
• falter
• halt
• hang back
• hesitate
• scruple
• shilly-shally
• stagger
• teeter
• waver
• wobble
• wabble

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

As the hours ticked by on Friday, reactions in Israel vacillated between extremes. —Ruth Margalit, New Yorker, 13 June 2025

Her Astrid is less a hewn warrior, more an uncertain teen, who vacillates between confidence and nervous energy. —Maureen Lee Lenker, EW.com, 10 June 2025

Or vacillating between tariffs of 145% to 30% in the space of a month, as happened recently with Chinese imports. —Michael Barclay, Quartz, 28 May 2025

While the secretary of state has tempered any optimism with reasons to be concerned that a lasting agreement between Vladimir Putin and Volodymyr Zelensky can be reached, the president has vacillated between public frustration and casual confidence. —David Catanese, Miami Herald, 6 May 2025

Word History

Etymology

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

Rhymes for vacillate

• abdicate
• abrogate
• acetate
• activate
• actuate
• adsorbate
• aggravate
• agitate
• alginate
• alienate
• allocate
• amputate

Kids Definition

vacillate

verb

vac·​il·​late ˈvas-ə-ˌlāt 

vacillated; vacillating

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

vacillation

ˌvas-ə-ˈlā-shən

noun

vacillator

ˈvas-ə-ˌlāt-ər 

noun