unpredictable
Americanadjective
noun
adjective
Other Word Forms
Etymology
Origin of unpredictable
First recorded in 1855–60; un- 1 + predictable
Explanation
When something's unpredictable, it doesn't happen at expected times or it can't be predicted. If trains were unpredictable, they wouldn't follow a set schedule and you'd never know when one would arrive. The adjective unpredictable can also describe something that's unexpected or not known in advance. Your soccer team's skill level might be wildly unpredictable — from game to game your coach never knows what you guys will do. It can be an insult if someone calls you an unpredictable person. That means people can't rely on you for things, such as consistently good work or keeping your promises.
Vocabulary lists containing unpredictable
Power Prefix: un-
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Speak
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Twenty Thousand Leagues Under the Sea
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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.
Industry experts say the slow and expensive production process owes to unpredictable congressional funding and indecisive Pentagon officials.
From The Wall Street Journal • Jun. 15, 2026
There’s no insurance product that will protect all your assets from the unpredictable, multiyear impact of serious health ailments.
From MarketWatch • Jun. 15, 2026
He said children could be unpredictable and parents should "always stay close" to them and "expect anything".
From BBC • Jun. 15, 2026
Movie industry watchers say their success shows that audiences are hungry for imaginative, unpredictable storytelling from fresh faces, rather than the big studios’ tired sequels and retreads.
From Barron's • Jun. 11, 2026
Who knew what horrible, unpredictable thing would happen next?
From "Flora & Ulysses: The Illuminated Adventures" by Kate DiCamillo
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.
