certainty

noun

cer·​tain·​ty ˈsər-tᵊn-tē 

plural certainties

1

: something that is certain

2

: the quality or state of being certain especially on the basis of evidence

Synonyms

• assurance
• confidence
• satisfaction
• conviction

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.

Recent Examples on the Web

This gives you certainty and a guarantee of progress. —Mark Travers, Forbes.com, 8 Aug. 2025

But instead of a decade of policy certainty as had been expected, federal tax credits for clean energy now are set to abruptly end after 2027. —Mike O’Boyle, Mercury News, 7 Aug. 2025

For soft-skill matters such as advice, sycophancy in AI chatbots can be especially dangerous, Cheng said, because there's no certainty about whether its guidance is sensible. —Emma Bowman, NPR, 5 Aug. 2025

Many have read Gödel and come away chastened by the limits of certainty—without concluding, as Richardson did, that the logical next step was to spend your life playing cards and paying prostitutes. —Adam Gopnik, New Yorker, 4 Aug. 2025

Word History

Etymology

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

First Known Use

14th century, in the meaning defined at sense 1

Phrases Containing certainty

• almost a certainty
• with certainty

Rhymes for certainty

• uncertainty

Kids Definition

certainty

noun

cer·​tain·​ty ˈsərt-ᵊn-tē 

plural certainties

1

: something certain

2

: the quality or state of being or feeling certain