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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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.
“Like many manufacturers, we are operating in a highly volatile and unpredictable tariff environment that continues to create uncertainty across the market,” said BRP CEO Denis Le Vot in a news release.
From Barron's • Apr. 15, 2026
A real strike on civilization as we know it occurred in Silicon Valley, where a new AI super-brain was locked up because it’s too powerful — and unpredictable.
From Los Angeles Times • Apr. 14, 2026
Project Servator has a proven track record of stopping criminals and terrorists through highly visible, unpredictable deployments that vary in time and location, deterring those planning harm and reassuring the public.
From BBC • Apr. 10, 2026
One of the largest and traditionally unpredictable costs is labor.
From The Wall Street Journal • Apr. 10, 2026
If you concentrate on controversy, then it begins to look as if progress in science is arbitrary and unpredictable.
From "The Invention of Science" by David Wootton
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.
