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.
Attorney Roberto Rallin rejected the prosecution's argument that Maradona's November 2020 death was foreseeable, while another defense attorney, Francisco Oneto, maintained that his death resulted from an "acute and unpredictable" heart attack.
From Barron's ● Oct. 21, 2026
This can suit a couple with the means and the willingness to live a more unpredictable lifestyle, especially in metropolitan areas.
From MarketWatch ● Oct. 19, 2026
Instead of constantly changing in an unpredictable way, these weather patterns appear to follow an underlying structure.
From Science Daily ● Oct. 17, 2026
The title is adapted by people who have never set eyes on the book to describe unpredictable behavior or contrasting appearances.
From The Wall Street Journal ● Oct. 16, 2026
High-strung and unpredictable, the prison warden labeled him a "troublemaker."
From Nazi Saboteurs by Samantha Seiple
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Get a wordDefinitions 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.
