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.
You can’t drill a well, build a factory, or extend credit without certainty that your contract will be honored and what you own today will be yours tomorrow.
From The Wall Street Journal • Jun. 8, 2026
But before the ball is in the air, the NBA Finals have already delivered one certainty: only in New York could Elmo, Trump, Mamdani and championship basketball all end up sharing the same storyline.
From Salon • Jun. 7, 2026
What’s behind SpaceX’s certainty that retail investors want to be a part of its IPO?
From MarketWatch • Jun. 5, 2026
"Amid global geopolitical pressures, the market needs certainty that monetary policy, financial supervision and market stabilisation remain independent and free from political intervention," added Central Bank Asia chief economist David Sumual.
From Barron's • Jun. 4, 2026
One hundred and ten lines from Scuto’s to home, same as always, a satisfying certainty.
From "Muffled" by Jennifer Gennari
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.
