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Synonyms

impossible

American  
[im-pos-uh-buhl] / ɪmˈpɒs ə bəl /

adjective

  1. not possible; unable to be, exist, happen, etc.

  2. unable to be done, performed, effected, etc..

    an impossible assignment.

  3. incapable of being true, as a rumor.

  4. not to be done, endured, etc., with any degree of reason or propriety.

    an impossible situation.

  5. utterly impracticable.

    an impossible plan.

  6. hopelessly unsuitable, difficult, or objectionable.

    Synonyms:
    unmanageable, intolerable, unbearable

impossible British  
/ ɪmˈpɒsəbəl /

adjective

  1. incapable of being done, undertaken, or experienced

  2. incapable of occurring or happening

  3. absurd or inconceivable; unreasonable

    it's impossible to think of him as a bishop

  4. informal intolerable; outrageous

    those children are impossible

"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 impossible

First recorded in 1250–1300; Middle English word from Latin word impossibilis. See im- 2, possible

Explanation

Something that's impossible can't be done. If you want to stop eating donuts but you just can't, you might say it's impossible. If it's impossible, it cannot happen, or it doesn't exist. You might wish you could bring Abraham Lincoln back to life for a day so he could come to tea, but that's impossible. People use the word impossible to mean "out of reach" or "too hard to achieve." A terrible situation can be impossible, and so can a person who refuses to compromise or seems intent on making things difficult for everyone else.

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Vocabulary lists containing impossible

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.

The clearer evening skies gave scientists an opportunity that had previously been impossible with older telescopes such as Hubble.

From Science Daily • May 27, 2026

“No, it’s impossible, because they go wherever they want to go.”

From Slate • May 27, 2026

Throughout his career, chronic dental problems had impacted his playing, but now pulmonary fibrosis had made playing impossible.

From The Wall Street Journal • May 26, 2026

It was "impossible not to feel deep sorrow when contemplating the immense suffering and humiliation endured by so many," the Pope wrote, adding that he "sincerely asked for pardon" in the name of the Church.

From BBC • May 25, 2026

She tried her best to please her parents, but it just seemed impossible.

From "Legendary Frybread Drive-In" by Cynthia Leitich Smith

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