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

Although the 27 members of the bloc voted in favor of the framework, many European leaders have since griped about it, and a long-term trade deal between the United States is far from a certainty. —David Goldman, CNN Money, 5 Sep. 2025

Intelligence emerges from states that exist between absolute certainty and random guessing through the combination of coherence, interference and ambiguity. —Sadhasivam Mohanadas, Forbes.com, 3 Sep. 2025

Where our certainty about anesthesia breaks down is in linking molecular changes to specific neural pathways, or in understanding the subjective experiences of a sleep-like state. —Rj MacKenzie, Popular Science, 3 Sep. 2025

The film doesn’t idealize the president as a man of unhesitating certainties. —David Rooney, HollywoodReporter, 2 Sep. 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