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Synonyms

unthinkable

American  
[uhn-thing-kuh-buhl] / ʌnˈθɪŋ kə bəl /

adjective

  1. inconceivable; unimaginable.

    the unthinkable size of the universe.

  2. not to be considered; out of the question.

    Such a suggestion is unthinkable.


noun

unthinkables plural
  1. something that cannot be conceived or imagined, as something too unusual, vague, or disagreeable.

    Today's unthinkables are tomorrow's realities.

unthinkable British  
/ ʌnˈθɪŋkəbəl /

adjective

  1. not to be contemplated; out of the question

  2. unimaginable; inconceivable

  3. unreasonable; improbable

"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

Derived Forms

Inflected Forms

Nouns

Etymology

Origin of unthinkable

late Middle English word dating back to 1400–50; see origin at un- 1, thinkable

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.

Why they wouldn’t prioritize Brink’s development alongside winning as they strive to snap a previously unthinkable five-year playoff drought.

From Los Angeles Times • Jun. 12, 2026

This has made unthinkable a conventional armored thrust to Tehran, along the lines of the 2003 U.S. invasion of Iraq.

From The Wall Street Journal • Jun. 10, 2026

"On one hand, it would have been unthinkable a few months ago that Jodar could even be competing in a Grand Slam," Spanish tennis journalist Alejandro Ciriza told BBC Sport.

From BBC • Jun. 1, 2026

E. Jean Carroll achieved the unthinkable and might end up paying a price for it.

From Slate • Jun. 1, 2026

That any of them could be true— literally true—seemed unthinkable.

From "Miss Peregrine's Home for Peculiar Children" by Ransom Riggs

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