un·cer·tain·ty | \ˌən-ˈsər-tᵊn-tē \

Definition of uncertainty 

1 : the quality or state of being uncertain : doubt

2 : something that is uncertain

Keep scrolling for more

Choose the Right Synonym for uncertainty

uncertainty, doubt, dubiety, skepticism, suspicion, mistrust mean lack of sureness about someone or something. uncertainty may range from a falling short of certainty to an almost complete lack of conviction or knowledge especially about an outcome or result. assumed the role of manager without hesitation or uncertainty doubt suggests both uncertainty and inability to make a decision. plagued by doubts as to what to do dubiety stresses a wavering between conclusions. felt some dubiety about its practicality skepticism implies unwillingness to believe without conclusive evidence. an economic forecast greeted with skepticism suspicion stresses lack of faith in the truth, reality, fairness, or reliability of something or someone. regarded the stranger with suspicion mistrust implies a genuine doubt based upon suspicion. had a great mistrust of doctors

Examples of uncertainty in a Sentence

There is some uncertainty about the company's future. He accepted the position without hesitation or uncertainty.

Recent Examples on the Web

His initial uncertainty about his identity is assuaged. The Economist, "A British traveller’s travelogue," 12 July 2018 The remedy for these uncertainties was a constitutional amendment, proposed by Congress and ratified by the individual states that provided for birthright citizenship. Martha S. Jones, Time, "How the 14th Amendment's Promise of Birthright Citizenship Redefined America," 9 July 2018 But a few hours into the music festival, one thing seems certain: The mystery and uncertainty continued. Samantha West, Milwaukee Journal Sentinel, "Eaux Claires Day 1 recap: The 'mystery' lineup is released, and some reply, 'Meh'," 6 July 2018 This enormous uncertainty leaves the Drake equation ultimately vulnerable to the optimism or pessimism of whoever wields it. Liv Boeree, Vox, "Why haven’t we found aliens yet?," 3 July 2018 Monroe is conversant in everything from quantum mechanics to evolution to cosmetology, and then can connect it all to the state of uncertainty that art museums across the country are currently facing. Jackie Mansky, Smithsonian, "The Neuroscientist in the Art Museum," 19 June 2018 Events like stock market corrections and geopolitical uncertainties could knock that down to 4 percent. Suzanne Woolley, ajc, "Millionaires now control half of the world's personal wealth," 14 June 2018 Commissioner for Economic and Financial Affairs, Taxation and Customs Pierre Moscovici said the downward revision was due to external factors such as U.S. trade uncertainty and high oil prices. Lucas Laursen, Fortune, "The EU Just Slashed the Eurozone Growth Forecast Because of U.S. Trade War Tensions," 12 July 2018 The primary issue is the presence of significant uncertainty and sudden decisions that get made. Matt Simon, WIRED, "Why Did the Human Cross the Road? To Confuse the Self-Driving Car," 10 July 2018

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

See More

First Known Use of uncertainty

14th century, in the meaning defined at sense 1

Keep scrolling for more

Learn More about uncertainty

Share uncertainty

Statistics for uncertainty

Last Updated

30 Sep 2018

Look-up Popularity

Time Traveler for uncertainty

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

See more words from the same century

Keep scrolling for more

More Definitions for uncertainty



English Language Learners Definition of uncertainty

: the quality or state of being uncertain

: something that is doubtful or unknown : something that is uncertain


un·cer·tain·ty | \ˌən-ˈsər-tᵊn-tē \
plural uncertainties

Kids Definition of uncertainty

1 : lack of certainty : doubt Uncertainty made the days of waiting longer …— William H. Armstrong, Sounder

2 : something that is doubtful or unknown Life is full of uncertainties.

Keep scrolling for more

Comments on uncertainty

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


evasion of direct action or statement

Get Word of the Day daily email!

Test Your Vocabulary

Great Scrabble Words—A Quiz

  • scrabble-tiles-that-read-scrabble-quiz
  • Which of the following Q-without-U words means the number five in cards or dice?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!


Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!