impossible
Americanadjective
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not possible; unable to be, exist, happen, etc.
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unable to be done, performed, effected, etc..
an impossible assignment.
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incapable of being true, as a rumor.
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not to be done, endured, etc., with any degree of reason or propriety.
an impossible situation.
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utterly impracticable.
an impossible plan.
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hopelessly unsuitable, difficult, or objectionable.
- Synonyms:
- unmanageable, intolerable, unbearable
adjective
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incapable of being done, undertaken, or experienced
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incapable of occurring or happening
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absurd or inconceivable; unreasonable
it's impossible to think of him as a bishop
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informal intolerable; outrageous
those children are impossible
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.
Vocabulary lists containing impossible
List 1
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myPerspectives 7.3
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im-
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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.
Many of these worlds are extremely difficult, or even impossible, to find using other detection methods.
From Science Daily • Jun. 1, 2026
"It's impossible that a law... can be applied in a way that is both flawless and fair" for the industry, she said.
From Barron's • May 31, 2026
It is fanciful, seeing as he has only reached the last 16 of a major for the first time, but not impossible given the men's draw continues to be blown wide open.
From BBC • May 29, 2026
If they tried to do that in the Boston metro area, it’s almost impossible because of the cost of living.
From The Wall Street Journal • May 29, 2026
And there was some paradox he remembered hearing about, something about a grandmother—oh, yeah, time travel had to be impossible because, otherwise, you could go back in time and kill your own grandmother.
From "Found" by Margaret Peterson Haddix
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
