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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.

See Examples For:

But I’ve come to love how Mitchell nailed being a nocturnal 20-something who winds up somewhere unpredictable whenever he leaves the apartment.

From Los Angeles Times Aug. 12, 2026

Hot weather can make travel unpredictable, and access issues can waste valuable time on an already exhausting day.

From BBC Aug. 11, 2026

In the streaming era, when music revenue has become increasingly unpredictable, merchandise has become a crucial income stream for artists.

From The Wall Street Journal Aug. 11, 2026

Since the markets are so unpredictable, it makes sense to divide your eggs among many baskets rather than bet on just one.

From MarketWatch Aug. 6, 2026

The answer was entirely unpredictable in 1543, but entirely inevitable after 1611.

From "The Invention of Science" by David Wootton

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