unpredictable
Americanadjective
noun
adjective
Other Word Forms
- unpredictability noun
- unpredictableness noun
- unpredictably adverb
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.
The pope made his strongest denunciation so far of the use of force on Saturday, calling out the “delusion of omnipotence that surrounds us and is becoming increasingly unpredictable and aggressive.”
From The Wall Street Journal • Apr. 12, 2026
In north London on Saturday, he was back to his familiarly unpredictable self.
From BBC • Apr. 12, 2026
The pope described the Kingdom of God as a "bulwark against that delusion of omnipotence that surrounds us and is becoming increasingly unpredictable and aggressive."
From Barron's • Apr. 11, 2026
Powered by Hamlet’s unpredictable emotions, the film cyclones toward a centerpiece dance performance: his “play” at the wedding of Claudius and Gertrude.
From Los Angeles Times • Apr. 10, 2026
As on the day the ship sank, after it had been thrown against the rocks, the waters in which the shattered vessel lies are cold and unpredictable.
From "Shipwrecked!" by Martin W. Sandler
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.
