un·​cer·​tain | \ ˌən-ˈsər-tᵊn \

Definition of uncertain

1a : 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

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Other Words from uncertain

uncertainly adverb
uncertainness \ ˌən-​ˈsər-​tᵊn-​(n)əs \ 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.
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Recent Examples on the Web

The plot began when Warren Harding was nominated to head the Republican ticket in 1920, but even today, the conspiracy’s precise scope remains uncertain. Andrew Coan, WSJ, "Why Robert Mueller’s Predecessors Usually Didn’t Prevail," 25 Jan. 2019 However, AlSayyad’s active employment status has remained uncertain as the internal investigation conducted through the Committee on Privilege and Tenure chugged along. Kelsey Keith, Curbed, "UC Berkeley suspends professor for sexual harassment, citing ‘voluminous evidence’," 21 Aug. 2018 The fate of Proposition C, a ballot measure that would raise taxes on commercial landlords in San Francisco to fund a variety of child care services, remained uncertain on Thursday, two days after voters went to the polls. Dominic Fracassa, SFChronicle.com, "SF’s Prop. C child-care measure still undecided, but lead has shrunk," 7 June 2018 But not everyone in Congress is on board, and the future of this Yemen resolution, and these similar measures is uncertain. Jen Kirby, Vox, "Senate debates resolution to end US support for war in Yemen," 13 Dec. 2018 The trajectory of her life and career are of course still uncertain, but Midge, bless her, seems unlikely to betray us. Marjorie Ingall, Town & Country, "The Marvelous Mrs. Maisel," 4 Dec. 2018 But with many Senators representing the anti-choice President Mauricio Macri’s party, Cambiemos, the outcome was uncertain ahead of the vote. Maria Puertas, Teen Vogue, "Argentina Abortion Vote: Senate Rejects Bill 38 to 31," 9 Aug. 2018 In an interview with golcaracol.com, the 29-year-old’s agent Lucas Jaramillo admitted that the shot stopper's career at the Emirates was uncertain. SI.com, "David Ospina's Agent Reveals 'Several Clubs' Interested in Signing Arsenal & Colombia Goalkeeper," 11 July 2018 But its future is uncertain, and the ruling essentially leaves decisions on implementing the law to the states in the near term. Kristina Peterson, WSJ, "Politicians Grapple With Response to Health Law Ruling," 16 Dec. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'uncertain.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of uncertain

14th century, in the meaning defined at sense 3

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Statistics for uncertain

Last Updated

3 Feb 2019

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Time Traveler for uncertain

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

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More Definitions for uncertain



English Language Learners Definition of uncertain

: not exactly known or decided : not definite or fixed
: not sure : having some doubt about something
: not definitely known


un·​cer·​tain | \ ˌən-ˈsər-tᵊn \

Kids Definition of uncertain

1 : not exactly known or decided on an uncertain amount
2 : not sure They were uncertain of the rules.
3 : not known for sure an uncertain claim
4 : likely to change : not dependable uncertain weather

Other Words from uncertain

uncertainly adverb

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