certainty
Americannoun
-
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
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.
"It's a near certainty this crocodile would have hunted Lucy's species. Whether a particular crocodile tried to grab Lucy, we'll never know, but it would have seen Lucy's kind and thought, 'Dinner.'"
From Science Daily • Jun. 13, 2026
Araghchi urged caution, telling Iranian state media that until a complete agreement was reached on all issues, "it cannot be said with certainty that an understanding has been achieved".
From Barron's • Jun. 13, 2026
The one certainty, despite her absence, was always England's diminutive right-hander.
From BBC • Jun. 12, 2026
Honestly, I’m dubious of the film’s certainty that folks even have the bandwidth to care about such news, let alone agree on what they’re seeing.
From Los Angeles Times • Jun. 10, 2026
Lena believed in girls with the same certainty that young yeshiva students believe in God.
From "Night Owls" by A.R. Vishny
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.
