certainty
Americannoun
-
certainties
plural
-
the state of being certain.
- Synonyms:
- confidence, assurance, certitude
-
something certain; an assured fact.
- Synonyms:
- truth
idioms
noun
-
the condition of being certain
-
something established as certain or inevitable
-
without doubt
Synonym Usage
See belief.
Other Word Forms
Derived Forms
Inflected Forms
Nouns
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.)
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.
See Examples For:
Scientists can’t say with certainty why this happens to some people and not others.
From The Wall Street Journal ● Oct. 9, 2026
However, this was pre-satellite monitoring so it is impossible to say with certainty that none formed.
From BBC ● Oct. 2, 2026
The engineer title evokes a sense of precision, control and certainty of outcomes that marketing for decades has been presumed to lack.
From The Wall Street Journal ● Sep. 30, 2026
“Without that legal certainty, every rule becomes another lawsuit, every standard becomes another risk, and the system keeps drifting toward a professional model.”
From Los Angeles Times ● Sep. 28, 2026
I felt my eyes water and knew with certainty that my teeth would be black for an hour.
From "The Detective's Assistant" by Kate Hannigan
For Holly Ratchford, all the certainties and securities of her years at Parkwood came to an abrupt end.
From BBC ● Aug. 29, 2026
“There are very few certainties or permanent decisions in my life right now,” he said.
From The Wall Street Journal ● Aug. 1, 2026
These calculations are useful, but they are estimates rather than certainties.
From MarketWatch ● May 26, 2026
AI systems produce probabilities, and people treat them as certainties.
From Salon ● May 12, 2026
An imposing congregation had massed itself around her first certainties, and now it was waiting and she could not disappoint it at the altar.
From "Atonement" by Ian McEwan
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
