Also found in: Thesaurus, Idioms.
Related to vacillation: Dominion, admonishment


intr.v. vac·il·lat·ed, vac·il·lat·ing, vac·il·lates
1. To be unable to choose between different courses of action or opinions; waver: She vacillated about whether to leave.
2. To change between one state and another; fluctuate: The weather vacillated between sunny and rainy.
3. Archaic To sway from one side to the other.

[Latin vacillāre, vacillāt-, to waver.]

vac′il·lat′ing·ly adv.
vac′il·la′tion n.
vac′il·la′tor n.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.



(see also RECANTATION.)

back and fill To vacillate, tergiversate; to blow hot and cold, to be wishy-washy. Back and fill is a nautical phrase describing a method of maneuvering a sailboat in which the sails are trimmed so that the wind strikes them first on the forward and then on the after side, so as to reduce forward movement. The figurative U.S. informal use of the phrase plays on the idea of the alternating forward and backward motion as opposed to a significant movement in any one direction. It is used to describe any lack of commitment to a particular point of view.

blow hot and cold To accept first, then reject; to seesaw, shilly-shally. This phrase stems from Aesop’s fable of a traveler who was entertained by a satyr. The traveler blew his fingers to warm them, and then with the same breath, blew his broth to cool it. Apparently the satyr was appalled to meet one who could blow both hot and cold, and said:

If you have gotten a trick of blowing hot and cold out of the same mouth, I’ve e’en done with ye. (R. Lestrange, Fables of Aesop, 1694)

As commonly used, blow hot and cold smacks less of hypocrisy than back and fill; it seems more natural and less manipulative.

Box and Cox Alternately sharing the same position, serving the same function or occupying the same space. Box and Cox, an 1847 farce by J. M. Morton, features two men—John Box and James Cox—who occupied the same apartment without being aware of each other’s existence. One worked the day shift and the other worked at night. The OED’s earliest citation for the phrase is from 1881.

Representing mind and body as playing a perpetual game of Box and Cox. (C. E. Raven, Creator Spirit, 1927)

The French Community … shares, Box-and-Coxwise, the Luxembourg Palace with the French Senate. (Spectator, August 14, 1959)

fall between two stools To be indecisive, to vacillate; to fail because of the inability to make a choice or decision. This expression implies that if someone cannot decide which of two stools to sit upon, he is likely to fall between them.

The unphilosophical attempt to sit upon two stools. (Joseph C. Neal, Charcoal Sketches, 1837)

The French equivalent, être assis entre deux chaises, means literally ‘to be seated between two chairs.’

hold with the hare and run with the hounds To straddle the fence; to play both ends against the middle; to get the best of both worlds. This hunting phrase is stronger than back and fill or blow hot and cold, implying an inability to commit one-self to one point of view, and an attempt to cover up by espousing both sides at once.

in dock, out nettle Inconstancy, vacillation, changeability, instability. This obsolete expression was originally part of a charm repeated while rubbing leaves of the herb dock into nettle stings in order to counteract any ill effects: “Nettle in, dock out, Dock in, nettle out, Nettle in, dock out, Dock rub nettle out.” An early figurative use of the expression is found in Nicholas Udall’s Ralph Roister Doister (1553):

I can not skill of such changeable mettle,

There is nothing with them but in dock out nettle.

Jekyll and Hyde One whose nature is contradictory—sometimes good and benevolent, other times evil and malevoient; a split personality; anything marked by the opposition of antagonistic forces. This popular phrase comes from Robert Louis Stevenson’s The Case of Dr. Jekyll and Mr. Hyde (1886). In this story, Jekyll appears as a kind, respectable character, Hyde as an ugly, despicable figure; however, both personalities belong to one man. The following quotation from the Times Literary Supplement (July 2, 1931) shows a current use of this phrase.

Turner was a case of Jekyll and Hyde in real life and oscillated continuously between the Victorian respectability of Bloomsbury … and the Rabelaisian society of the London Docks.


on the fence Undecided, especially in regard to political issues. This expression alludes to the dilemma of a person atop a wall who must decide which is the safer side to descend. In contemporary usage, this American slang phrase usually describes a politician who waits to see how an issue fares before committing his support in either direction.

Now all would-but-dare-not-be-politicians who insist in sitting on the fence, will be amerced a penalty for the same. (Annals of Cleveland, 1830)

a reed shaken by the wind A spineless, wishy-washy person whose opinions shift with the prevailing political or conventional winds; a tergiversator. As currently used, the image stands on its own; the phrase bears no relationship to the New Testament context in which it was spoken by Jesus regarding John the Baptist.

“What went ye out into the wilderness to see? A reed shaken with the wind?” (Matthew 11:7)

shilly-shally To vacillate between two ways of thinking or acting; to dally with trifles to avoid making a decision. The original phrase was shall I, shall I, which was altered to shill I, shall I. The present form of shilly-shally was used as early as the 1700s. It is an innocuous phrase which, like blow hot and cold, suggests no hypocrisy or manipulative behavior.

To shilly-shally on the matter, to act in one way today and in a different way tomorrow. (F. W. Farrar, Life and Work of St. Paul, 1879)

weathercock A person of wavering principles; an indecisive person; a trend follower. In the 9th century, a papal decree ordered each church to place the likeness of a cock atop its steeple in allusion to St. Peter’s triple denial of Jesus before the cock crowed twice. After a time, these cocks were mounted on pivots so that they pointed to the direction from which the wind was blowing. Thus, weathercock acquired the sense of something being directed by the fancy of the prevailing wind. The term, used figuratively since the time of Chaucer, still carries its meaning of one of vacillating principles.

He was … a terrible weathercock in the matter of opinion. (Robert Brough, Marston Lynch, 1870)

The expression’s figurative meaning has been extended to include a person who quickly adopts the latest styles and fads, perhaps as an analogy between the ever-changing directions of the fashion world.

Picturesque Expressions: A Thematic Dictionary, 1st Edition. © 1980 The Gale Group, Inc. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.vacillation - indecision in speech or actionvacillation - indecision in speech or action  
indecision, indecisiveness, irresolution - doubt concerning two or more possible alternatives or courses of action; "his indecision was only momentary but the opportunity was lost"
2.vacillation - changing location by moving back and forthvacillation - changing location by moving back and forth
movement, move, motion - the act of changing location from one place to another; "police controlled the motion of the crowd"; "the movement of people from the farms to the cities"; "his move put him directly in my path"
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.


noun indecisiveness, hesitation, irresolution, wavering, dithering (chiefly Brit.), fluctuation, unsteadiness, inconstancy, shillyshallying (informal), irresoluteness The Prime Minister was pilloried for vacillation and weakness.
"Some praise at morning what they blame at night;"
"But always think the last opinion right" [Alexander Pope An Essay on Criticism]
"Don't change horses in midstream"
Collins Thesaurus of the English Language – Complete and Unabridged 2nd Edition. 2002 © HarperCollins Publishers 1995, 2002


The American Heritage® Roget's Thesaurus. Copyright © 2013, 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


[ˌvæsɪˈleɪʃən] Nvacilación f
Collins Spanish Dictionary - Complete and Unabridged 8th Edition 2005 © William Collins Sons & Co. Ltd. 1971, 1988 © HarperCollins Publishers 1992, 1993, 1996, 1997, 2000, 2003, 2005


[ˌvæsɪˈleɪʃən] nhésitation f
Collins English/French Electronic Resource. © HarperCollins Publishers 2005


nSchwanken nt; (fig also)Unentschlossenheit f, → Unschlüssigkeit f
Collins German Dictionary – Complete and Unabridged 7th Edition 2005. © William Collins Sons & Co. Ltd. 1980 © HarperCollins Publishers 1991, 1997, 1999, 2004, 2005, 2007
References in classic literature ?
He honestly mistook his sensuality for romantic emotion, his vacillation for the artistic temperament, and his idleness for philosophic calm.
The vacillation between the various plans that were proposed had even increased after the Emperor had been at headquarters for a month.
On the whole his surmises, in addition to what he knew of the fact, increased his friendliness and tolerance towards Ladislaw, and made him understand the vacillation which kept him at Middlemarch after he had said that he should go away.
There is vacillation in his k's and self-esteem in his capitals.
As he proceeded, the company grew more scattered, and his old uneasiness and vacillation were resumed.
Hearing these decisive and terrible words, Lady Macbeth, who had been waiting for a sign of weakness or vacillation on the part of her son-in-law, rose and, with a scared look, left the library.
From the near vision of that certainty he fell back on suspense and vacillation with a sense of repose.
For a long period the latter had the upper hand, and his life has been described by his best editor, Professor George Herbert Palmer, as twenty-seven years of vacillation and three of consecrated service.
In the mean time, the unconscious Ellen herself moved about the feeble and less resolute Inez, with her accustomed assiduity and tenderness, exhibiting in her frank features those changing emotions of joy and regret which occasionally beset her, as her active mind dwelt on the decided step she had just taken, with the contending doubts and hopes, and possibly with some of the mental vacillation, that was natural to her situation and sex.
Vacillation of purpose was not at all unusual in her experience of her master.
He noticed the vacillation of surprise passing over the steady curiosity of the black eyes fastened on his face as if the woman revolutionist received the sound of his voice into her pupils instead of her ears.
It may be but an idle whim, but it has always seemed to me, that the extraordinary vacillations of movement displayed by some whales when beset by three or four boats; the timidity and liability to queer frights, so common to such whales;