uncertain

adjective

un·​cer·​tain ˌən-ˈsər-tᵊn How to pronounce uncertain (audio)
1
a
: not known beyond doubt : dubious
an uncertain claim
b
: not having certain knowledge : doubtful
remains uncertain about her plans
c
: not clearly identified or defined
a fire of uncertain origin
2
: not constant : variable, fitful
an uncertain breeze
3
: indefinite, indeterminate
the time of departure is uncertain
4
: not certain to occur : problematical
his success was uncertain
5
: not reliable : untrustworthy
an uncertain ally
uncertainly adverb
uncertainness noun

Examples of uncertain in a Sentence

The time of departure is still uncertain. We are still uncertain of the truth. She remains uncertain about her plans. I'm uncertain about how to respond. The cause of the fire is uncertain. He has an uncertain temper. They face a financially uncertain future.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Culture provides a grip in an uncertain world, whether racing through growth or crisis mode. Umang Modi, Forbes.com, 7 July 2025 The future is uncertain for both the league and its players. Julia Poe, Chicago Tribune, 7 July 2025 This enormous — and uncertain — data center growth should not be Maryland’s responsibility. David S. Lapp, Baltimore Sun, 7 July 2025 According to a survey conducted for the American Institute of Certified Public Accountants, more than 70% of Americans have felt either cautious or uncertain about their financial situation over the past 12 months. Corina Vanek, AZCentral.com, 7 July 2025 See All Example Sentences for uncertain

Word History

First Known Use

14th century, in the meaning defined at sense 3

Time Traveler
The first known use of uncertain was in the 14th century

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Cite this Entry

“Uncertain.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/uncertain. Accessed 11 Jul. 2025.

Kids Definition

uncertain

adjective
un·​cer·​tain ˌən-ˈsərt-ᵊn How to pronounce uncertain (audio)
ˈən-
1
: not definite or fixed
an uncertain quantity
2
a
: not sure
uncertain of the truth
b
: not known for sure
an uncertain claim
3
: likely to change : not dependable
uncertain weather
uncertainly adverb

More from Merriam-Webster on uncertain

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