impossible
Americanadjective
-
not possible; unable to be, exist, happen, etc.
-
unable to be done, performed, effected, etc..
an impossible assignment.
-
incapable of being true, as a rumor.
-
not to be done, endured, etc., with any degree of reason or propriety.
an impossible situation.
-
utterly impracticable.
an impossible plan.
-
hopelessly unsuitable, difficult, or objectionable.
- Synonyms:
- unmanageable, intolerable, unbearable
adjective
-
incapable of being done, undertaken, or experienced
-
incapable of occurring or happening
-
absurd or inconceivable; unreasonable
it's impossible to think of him as a bishop
-
informal intolerable; outrageous
those children are impossible
Other Word Forms
Derived 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
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
myPerspectives 7.3
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
im-
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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.
It is nearly impossible to quantify how much oil demand has been destroyed during the war.
From Barron's • Jun. 9, 2026
The catch is that you need credit to build credit, which sometimes can make getting started feel impossible.
From MarketWatch • Jun. 9, 2026
Jamie said he felt it was impossible to be assertive with the gang because of his condition.
From BBC • Jun. 8, 2026
But that illusion is impossible if all of space-time occurs in a flash.
From Science Daily • Jun. 8, 2026
It was impossible for a moment to understand what had happened.
From "Woodsong" by Gary Paulsen
![]()
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.