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Synonyms

unpredictable

American  
[uhn-pri-dik-tuh-buhl] / ˌʌn prɪˈdɪk tə bəl /

adjective

  1. not predictable; not to be foreseen or foretold.

    an unpredictable occurrence.

    Synonyms:
    uncertain, variable, fitful, erratic

noun

  1. something that is unpredictable.

    the unpredictables of life.

unpredictable British  
/ ˌʌnprɪˈdɪktəbəl /

adjective

  1. not capable of being predicted; changeable

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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.

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Vocabulary lists containing unpredictable

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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