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

In typical New England fashion, the sky vacillated from a blanket of gray to light blue. —Laura Tillman, Hartford Courant, 5 May 2025

During a turbulent Game 6 closeout of the Pistons, one in which the Knicks vacillated between superiority and forgetting how to play the sport, Bridges’ physicality was a constant. —Fred Katz, New York Times, 3 May 2025

His vacillating trade policy has undermined consumer and business confidence, and caused economists to raise their forecasts for a U.S. recession. —Chris Prentice, USA Today, 19 Apr. 2025

Supernatural vacillated wildly in quality over its 300+ episodes but there are some true gems in here, especially for fans of urban legends and things that go bump in the night. —Brian Tallerico, Vulture, 18 Mar. 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