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Synonyms

improbable

American  
[im-prob-uh-buhl] / ɪmˈprɒb ə bəl /

adjective

  1. not probable; unlikely to be true or to happen.

    Rain is improbable tonight.

    Synonyms:
    implausible, doubtful, questionable

improbable British  
/ ɪmˈprɒbəbəl /

adjective

  1. not likely or probable; doubtful; unlikely

"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 improbable

From the Latin word improbābilis, dating back to 1590–1600. See im- 2, probable


Explanation

Your parents might tell you it's improbable that they'll buy you a car when you turn 16. Since improbable means something is unlikely but not impossible, your optimism allows you to keep hoping. The adjective improbable also means statistically unlikely to happen. You might be afraid to fly, but the odds of a plane crash are so low that such an event is improbable. Improbable also means something that is so outrageous that you'd never admit you believed in it. You know the existence of the Loch Ness Monster is improbable, but that doesn't stop you from looking for it when you travel to Scotland.

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Vocabulary lists containing improbable

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:

Instead, Bridget Devaney turned to the internet with a proposal that sounded equal parts hopeful and improbable - come to Northern Ireland and celebrate the wedding that never happened.

From BBC ● Oct. 31, 2026

The improbable evening turned into a moving tribute to both Capra himself and his tale of the suicidal banker George Bailey, who comes to realize that his life has indeed been wonderful.

From Los Angeles Times ● Oct. 27, 2026

Surrounded by the windswept desert and towering mountains, locals are keenly aware of how improbable it was that a bustling town and verdant fields arose in this unforgiving terrain—and how swiftly it all might disappear.

From The Wall Street Journal ● Oct. 21, 2026

Her improbable rise to become Florida’s Democratic nominee for U.S.

From Salon ● Oct. 21, 2026

In the New Orleans show, I felt all the amusement of the improbable abnormal, but also a kind of horror that it could be so.

From "Travels with Charley in Search of America" by John Steinbeck

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