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

Cnet recently celebrated the station’s anniversary with a retrospective, while noting its uncertain future under the Trump administration. Adi Robertson, The Verge, "Furby hell: this week in tech, 20 years ago," 24 Nov. 2018 The move comes as Sears’s uncertain future is being debated by some of the retailer’s creditors. Lillian Rizzo, WSJ, "Sears Proposes Bonus Package for Top Executives," 19 Nov. 2018 When it was reported last month that a spousal work ban is coming in three months, I was suddenly faced with an uncertain future. Diya Khanna, The Seattle Times, "When you want to work, but can’t," 23 Oct. 2018 But even employees like John Germann, whose store in Chicago Ridge, Illinois, has been spared for now, is feeling uncertain about his future. Anne D'innocenzio, The Seattle Times, "Sears’ bankruptcy will have ripple effect, not all of it bad," 16 Oct. 2018 Many variables are still uncertain about the tournament, including recent reports that FIFA might accelerate its intention to expand the number of teams from 32 to 48. Hayden Bird, BostonGlobe.com, "What to know about the World Cup title match," 14 July 2018 Shea is currently uncertain about what type of technology can be used to tally hot dogs and buns. Jenna West, SI.com, "Digital Technology Considered for Nathan's Hot Dog Eating Contest After Miscount," 5 July 2018 But the researchers are uncertain about the composition and slipperiness of that geologic bowl. Paul Voosen, Science | AAAS, "U.S.-U.K. science armada to target vulnerable Antarctic ice sheet," 30 Apr. 2018 The men are young and uncertain about what would happen. Alex Horton, Philly.com, "Before video of a Starbucks arrest, images of lunch counter sit-ins helped launch a movement," 17 Apr. 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

8 Dec 2018

Look-up Popularity

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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Comments on uncertain

What made you want to look up uncertain? Please tell us where you read or heard it (including the quote, if possible).


to enclose within walls

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