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

There is emotional intensity, to be sure, given the enormous stakes and the virtual certainty that Kavanaugh's confirmation would significantly shift the high court to the right. Howard Kurtz, Fox News, "Kavanaugh's baseball debts: Why the nominee's opponents are striking out," 13 July 2018 That didn’t happen as the Orioles are on pace for one of the worst seasons in major league history, and their focus has turned to rebuilding for the future, making moving Machado a near certainty. Eduardo A. Encina, baltimoresun.com, "As trade talk swirls around him, Orioles' Manny Machado elected to start All-Star Game," 8 July 2018 But more certainty has developed over the last few years. David Fleshler, latimes.com, "The world has never seen a Category 6 hurricane. But the day may be coming," 7 July 2018 Charlotte will pad its average this week, with a capacity crowd almost a certainty for Wednesday night’s Independence Day game (followed by the SkyShow fireworks display) against Durham. Steve Lyttle, charlotteobserver, "Charlotte Knights are on a quest to reclaim a minor-league title. Fireworks can help.," 1 July 2018 Members of the congregation also have some certainty about the future of the building: The Hope Tabernacle Apostolic Church, which has leased space there since 2011, has made an offer to buy it. Steven Goode, Courant Community, "End of An Era for Windsor Synagogue," 24 June 2018 As if one isn’t part of anything which might claim certainty -- neither the hospital nor the stadium. Nyay Bhushan, The Hollywood Reporter, "Irrfan Khan Shares Details of His Battle With Rare Cancer," 19 June 2018 That’s a controversial idea to say the least, flying in the face of years of official near-certainty about a southern terminus. Jeff Wise, Popular Mechanics, "What If They Were Looking for Malaysia Airlines Flight 370 in the Wrong Place All Along?," 8 June 2018 Volcanologist Janine Krippner suspects the magma is either moving to a different storage area in the volcano or to the East Rift Zone, where fissures have been oozing lava, but the magma's movements can't be predicted with complete certainty. Sarah Gibbens, National Geographic, "Will the Eruptions From Hawaii's Kilauea Volcano Turn Explosive? Get the Facts.," 10 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

10 Nov 2018

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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

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


something that serves to warn or remind

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