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Showing results for uncertain. Search instead for incertain.
Synonyms

uncertain

American  
[uhn-sur-tn] / ʌnˈsɜr tn /

adjective

  1. not definitely ascertainable or fixed, as in time of occurrence, number, dimensions, or quality.

    Synonyms:
    unpredictable, unsure
  2. not confident, assured, or free from hesitancy.

    an uncertain smile.

  3. not clearly or precisely determined; indefinite; unknown.

    a manuscript of uncertain origin.

    Synonyms:
    undetermined, unsettled
  4. vague; indistinct; not perfectly apprehended.

    an abstruse novel with uncertain themes.

  5. subject to change; variable; capricious; unstable.

    a person of uncertain opinions.

  6. ambiguous; unreliable; undependable.

    Her loyalties are uncertain.

  7. dependent on chance or unpredictable factors; doubtful; of unforeseeable outcome or effect.

  8. unsteady or flickering, as light; of changing intensity or quality.

    Synonyms:
    irregular

uncertain British  
/ ʌnˈsɜːtən /

adjective

  1. not able to be accurately known or predicted

    the issue is uncertain

  2. not sure or confident (about)

    a man of uncertain opinion

  3. not precisely determined, established, or decided

    uncertain plans

  4. not to be depended upon; unreliable

    an uncertain vote

  5. liable to variation; changeable

    the weather is uncertain

    1. unambiguously

    2. forcefully

"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

uncertain Idioms  

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

In this uncertain context, Poland's subsoil appears to be a major asset for the energy sovereignty of the Old Continent.

From Barron's • 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

But it has been especially hard for the millions of migrants whose futures have now turned uncertain.

From BBC • Mar. 31, 2026

Her heartbeat stuttered in her chest as she stopped before it, uncertain.

From "Beasts of Prey" by Ayana Gray