unpredictable
Americanadjective
noun
adjective
Other Word Forms
Derived 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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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.
Forecasters are expecting scorching and unpredictable conditions in the US this summer, fuelled by El Nino, a weather phenomenon which causes erratic fluctuations in the weather in the US and elsewhere.
From BBC • Jun. 11, 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
“Will they keep the theme tune? Will they lose the blue box? Will they bring back the Drahvin?! It’s all up for grabs, which is so Doctor Who, exciting and unpredictable and new!”
From Los Angeles Times • Jun. 10, 2026
Aging and disease are unpredictable, and who knows how any of us will fare.
From The Wall Street Journal • Jun. 9, 2026
Vincent's life is as unpredictable as his eccentricities.
From "Vincent and Theo: The Van Gogh Brothers" by Deborah Heiligman
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.
