cer·​tain·​ty | \ ˈsər-tᵊn-tē \
plural certainties

Definition of certainty 

1 : something that is certain
2 : the quality or state of being certain especially on the basis of evidence

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Choose the Right Synonym for certainty

certainty, certitude, conviction mean a state of being free from doubt. certainty and certitude are very close; certainty may stress the existence of objective proof claims that cannot be confirmed with scientific certainty , while certitude may emphasize a faith in something not needing or not capable of proof. believes with certitude in an afterlife conviction applies especially to belief strongly held by an individual. holds firm convictions on every issue

Examples of certainty in a Sentence

Scientists still do not know with any degree of certainty why the disease spread so quickly. We cannot predict the outcome with absolute certainty. There was no certainty that the package would arrive in time. Her certainty about these complex moral issues is surprising.
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Recent Examples on the Web

One certainty is the end of pro-growth legislation. The Editorial Board, WSJ, "Enter the House of Pelosi," 2 Jan. 2019 What is surprising, however, is the sense of certainty that many conservative evangelicals have about exactly why their God has allowed Donald Trump to be president. Tara Isabella Burton, Vox, "Historian and author John Fea on Trump’s “court evangelicals” and the long history of Christian nationalism.," 5 Nov. 2018 Colder weather brings with it one certainty for air travelers: the start of space wars. Christopher Elliott, The Seattle Times, "Travel Wise | On airplanes, personal space is a vanishing commodity. Here’s how to cope.," 22 Oct. 2018 The aftermath produced one certainty: Congress is hopelessly split in conducting executive branch oversight of the Trump administration. Andrew O'reilly, Fox News, "Trumps blasts FBI Agent Strzok as 'disgrace to our country'," 15 July 2018 The one certainty is if Democrats capture the House and/or the Senate majorities in November, Wall Street is in for a tougher audience than the past few years. Paul Kane, Washington Post, "The Finance 202: Key financial panels on Capitol Hill may have new leaders come November," 21 June 2018 That spending reflects one certainty: U.S. businesses have more money because of the tax changes. Jim Puzzanghera, latimes.com, "Businesses hiked spending after the tax bill, but the U.S. economy still awaits that promised big boost," 8 June 2018 Should another hurricane hit Puerto Rico, there is one certainty: its power grid will collapse. Leyla Santiago, CNN, "Still mending Maria's mess, Puerto Rico braces for a new hurricane season," 1 June 2018 But one certainty remains: Sports must remain pure in their purpose as a contest of what athletes give in a game, not what betting can take from them. The Christian Science Monitor, "Mixing sports and sports gambling is no game," 14 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'certainty.' 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 certainty

14th century, in the meaning defined at sense 1

History and Etymology for certainty

Middle English certeinte, borrowed from Anglo-French certeinté, from certein, certain certain entry 1 + -té -ty

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Statistics for certainty

Last Updated

6 Jan 2019

Look-up Popularity

Time Traveler for certainty

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

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More Definitions for certainty



English Language Learners Definition of certainty

: the state of being or feeling certain about something

: something that is certain : a fact about which there is no doubt


cer·​tain·​ty | \ ˈsər-tᵊn-tē \
plural certainties

Kids Definition of certainty

1 : something that is sure Victory was a certainty.
2 : the quality or state of being sure She answered with certainty.

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Comments on certainty

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