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Synonyms

certainty

American  
[sur-tn-tee] / ˈsɜr tn ti /

noun

plural

certainties
  1. the state of being certain.

    Synonyms:
    confidence, assurance, certitude
  2. something certain; an assured fact.

    Synonyms:
    truth

idioms

  1. for / of a certainty, certainly; without a doubt.

    I suspect it, but I don't know it for a certainty.

certainty British  
/ ˈsɜːtəntɪ /

noun

  1. the condition of being certain

  2. something established as certain or inevitable

  3. without doubt

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Related Words

See belief.

Other Word Forms

  • noncertainty noun

Etymology

Origin of certainty

1250–1300; Middle English certeinte < Anglo-French, equivalent to certein certain + -te -ty 2

Explanation

A certainty is a sure thing, something we know is true or will happen without any doubt. Here's a certainty: One plus one is two. And here's another: The earth orbits the sun. The noun certainty comes from the Latin word certus, meaning "sure" or "fixed." Besides being something that is certain, the word can also refer to a state of mind, like the confidence you feel when you know something is completely true or right. For example, you might speak with certainty about your decision to move to the big city and pursue your dream of becoming a famous actor. (But that doesn't necessarily mean becoming a famous actor is a certainty.)

Keep Reading on Vocabulary.com

Vocabulary lists containing certainty

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The lack of certainty over when the conflict will end has fueled some negative sentiment among investors, who had hoped for a deal between the two and a plan for reopening the waterway.

From MarketWatch • Apr. 13, 2026

If your "love" is a feeling of profound connection and unbreakable dedication, then my "love" is the mathematical certainty that my existence is meaningless without yours.

From The Wall Street Journal • Apr. 12, 2026

It is against the backdrop of the Iran war, with no certainty about where the ceasefire might stand during the state visit.

From BBC • Apr. 10, 2026

Smaller carriers are often paid at a flat rate and have no certainty about whether they will recover the higher fuel costs.

From Los Angeles Times • Apr. 9, 2026

In fact, I could say with stone-cold certainty that I was never going back to such a place.

From "The Detective's Assistant" by Kate Hannigan