[ vas-uh-ley-ting ]
/ ˈvæs əˌleɪ tɪŋ /


not resolute; wavering; indecisive; hesitating: an ineffectual, vacillating person.
oscillating; swaying; fluctuating: a vacillating indicator.

Nearby words

  1. vaccinology,
  2. vachel,
  3. vacherin,
  4. vacillant,
  5. vacillate,
  6. vacillation,
  7. vacillatory,
  8. vacterl syndrome,
  9. vacua,
  10. vacuity

Also vacillant.

Origin of vacillating

First recorded in 1805–15; vacillate + -ing2

Related formsvac·il·lat·ing·ly, adverbnon·vac·il·lat·ing, adjectiveun·vac·il·lat·ing, adjective


[ vas-uh-leyt ]
/ ˈvæs əˌleɪt /

verb (used without object), vac·il·lat·ed, vac·il·lat·ing.

to waver in mind or opinion; be indecisive or irresolute: His tendency to vacillate makes him a poor leader.
to sway unsteadily; waver; totter; stagger.
to oscillate or fluctuate.

Origin of vacillate

1590–1600; < Latin vacillātus (past participle of vacillāre to sway to and fro); see -ate1

Related formsvac·il·la·tor, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for vacillating

British Dictionary definitions for vacillating


rarely vacillant (ˈvæsɪlənt)

/ (ˈvæsɪˌleɪtɪŋ) /


inclined to waver; indecisive
Derived Formsvacillatingly, adverb


/ (ˈvæsɪˌleɪt) /

verb (intr)

to fluctuate in one's opinions; be indecisive
to sway from side to side physically; totter or waver
Derived Formsvacillation, nounvacillator, noun

Word Origin for vacillate

C16: from Latin vacillāre to sway, of obscure origin

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for vacillating



1590s, "to sway unsteadily," from Latin vacillatum, from vacillare (see vacillation). Meaning "to waver between two opinions or courses" is recorded from 1620s. Related: Vacillated; vacillates; vacillating.

Online Etymology Dictionary, © 2010 Douglas Harper