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

What if leadership looked less like certainty — and more like honesty? —Rochelle Ratkaj, Rolling Stone, 3 Oct. 2025

Wall Street holds near record highs in a government-data blackout , with enough rotational energy toward left-behind groups, refreshed confidence in the AI spending frenzy, certainty of a Fed rate cut this month and speculative aggression in lower-quality longshots to keep the indexes aloft. —Michael Santoli, CNBC, 3 Oct. 2025

The Pontifical Academies also warned that delay raises systemic risks (economic, social, and health related) echoing the investor logic that policy certainty lowers risk premia. —Felicia Jackson, Forbes.com, 3 Oct. 2025

Early on, astronomers were able to determine with a high degree of certainty that the object is a comet, but work has continued to get a better idea of its size and phyisical characteristics. —Eric Lagatta, USA Today, 2 Oct. 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