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
-
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unambiguously
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forcefully
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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.
“The breadth of demand says that gold remains a compelling investment in today’s uncertain and increasingly dangerous world,” said Ash.
From MarketWatch • Apr. 4, 2026
When Galsworthy created “The Man of Property,” he was 35 years old, had published two largely unnoticed novels, and had no reason to imagine he was embarking on anything more than another uncertain literary venture.
From The Wall Street Journal • Apr. 3, 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
It is also uncertain when U.S. gas prices — which jumped past an average of $4 a gallon this week for the time since 2022 — would go lower.
From Los Angeles Times • Apr. 1, 2026
Sara seems as uncertain as I am, but I notice she’s not pulling at her sleeve anymore.
From "A Place at the Table" by Saadia Faruqi and Laura Shovan
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.
