uncertain
Americanadjective
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not definitely ascertainable or fixed, as in time of occurrence, number, dimensions, or quality.
- Synonyms:
- unpredictable, unsure
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not confident, assured, or free from hesitancy.
an uncertain smile.
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not clearly or precisely determined; indefinite; unknown.
a manuscript of uncertain origin.
- Synonyms:
- undetermined, unsettled
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vague; indistinct; not perfectly apprehended.
an abstruse novel with uncertain themes.
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subject to change; variable; capricious; unstable.
a person of uncertain opinions.
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ambiguous; unreliable; undependable.
Her loyalties are uncertain.
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dependent on chance or unpredictable factors; doubtful; of unforeseeable outcome or effect.
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unsteady or flickering, as light; of changing intensity or quality.
- Synonyms:
- irregular
adjective
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not able to be accurately known or predicted
the issue is uncertain
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not sure or confident (about)
a man of uncertain opinion
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not precisely determined, established, or decided
uncertain plans
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not to be depended upon; unreliable
an uncertain vote
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liable to variation; changeable
the weather is uncertain
-
-
unambiguously
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forcefully
-
Related Words
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.
Other Word Forms
- uncertainly adverb
- uncertainness noun
Etymology
Origin of uncertain
First recorded in 1250–1300; Middle English; un- 1 + certain
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Finding a well-paid job is important, but so is a sense of job security at an uncertain time for the economy, according to labor-market experts and a growing number of surveys.
From MarketWatch • Apr. 3, 2026
Given current challenges facing NASA, the timeline remains uncertain.
From Science Daily • Apr. 3, 2026
Some parents are hesitant to lock money into college-savings accounts, preferring financial flexibility in an uncertain world.
From The Wall Street Journal • Apr. 1, 2026
The environment is simply too uncertain for anyone to conclude that they must buy stocks for fear of missing out.
From Barron's • Apr. 1, 2026
The Russian spotted a police officer and, as quickly as he appeared, disappeared into the night, leaving the two Americans with the envelope, uncertain what to do.
From "Spies: The Secret Showdown Between America and Russia" by Marc Favreau
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
