- not definitely ascertainable or fixed, as in time of occurrence, number, dimensions, or quality.
- not confident, assured, or free from hesitancy: an uncertain smile.
- not clearly or precisely determined; indefinite; unknown: a manuscript of uncertain origin.
- vague; indistinct; not perfectly apprehended: an abstruse novel with uncertain themes.
- subject to change; variable; capricious; unstable: a person of uncertain opinions.
- ambiguous; unreliable; undependable: Her loyalties are uncertain.
- dependent on chance or unpredictable factors; doubtful; of unforeseeable outcome or effect.
- unsteady or flickering, as light; of changing intensity or quality.
Origin of uncertain
SynonymsSee more synonyms on Thesaurus.com
1. unsure, unpredictable. 3. unsettled, undetermined. 8. irregular.
1. Uncertain, insecure, precarious imply a lack of predictability. That which is uncertain is doubtful or problematical; it often involves danger through an inability to predict or to place confidence in the unknown: The time of his arrival is uncertain. That which is insecure is not firm, stable, reliable, or safe, and hence is likely to give way, fail, or be overcome: an insecure foundation, footing, protection. Precarious suggests great susceptibility to failure, or exposure to imminent danger: a precarious means of existence.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for uncertain
In war, he wrote, “everything is uncertain … all military action is intertwined with psychological forces and effects.”How Clausewitz Invented Modern War
James A. Warren
November 24, 2014
“The jailer had a high-school-age daughter and was uncertain how to help her get in college,” writes Ferris.The Tragic History of Southern Food
November 12, 2014
Meanwhile, ISIS is on the march, and President Obama strikes an uncertain pose.Iowa Frontrunner Mike Huckabee Talks to The Daily Beast
September 22, 2014
Even “destroyed” becomes an uncertain term when applied to these sort of digital files.Your Arrest Video Is Going Online. Who Will See It?
September 11, 2014
Whether this three-day system is a harbinger of seasonal weather changes is uncertain.A Cloud Forms Over Saturn’s Mysterious Moon
Matthew R. Francis
August 17, 2014
You may have noticed that night at the Oldakers'—well, women, Mr. Bines, are uncertain.The Spenders
Harry Leon Wilson
There appears to be a great number of horses', but am uncertain if there are any camel-tracks.Explorations in Australia
With his bag in hand, he wandered through the streets, uncertain what to do or where to go.Life in London
Her face was close to his, else he could not have caught the uncertain murmuring.Within the Law
Then some one—who it was is uncertain—ordered the bugler to sound the "charge."The Story of the Malakand Field Force
Sir Winston S. Churchill
- not able to be accurately known or predictedthe issue is uncertain
- (when postpositive, often foll by of) not sure or confident (about)a man of uncertain opinion
- not precisely determined, established, or decideduncertain plans
- not to be depended upon; unreliablean uncertain vote
- liable to variation; changeablethe weather is uncertain
- in no uncertain terms
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 uncertain
Online Etymology Dictionary, © 2010 Douglas Harper
Idioms and Phrases with uncertain
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.