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.
Rather than the unpredictable hints that preceded the 2024 unwind, the BoJ has intervened more regularly so far this year and has been “more active in the market,” Getter told MarketWatch in a phone interview.
From MarketWatch • Jul. 2, 2026
A plush toy may be dependent on unpredictable consumer spending, but the underlying business model is built on revenue stemming from royalties, Collins said.
From The Wall Street Journal • Jun. 30, 2026
Settings like this are a good place to start, since they’re controlled environments that involve plenty of repetition, rather than unpredictable elements.
From Barron's • Jun. 30, 2026
On an unpredictable surface, with such a huge target, there will not be one last chase as a Stokes send-off.
From BBC • Jun. 28, 2026
Though I doubted my fate would be so drastic, the man was unpredictable.
From "The Shakespeare Stealer" by Gary L. Blackwood
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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.