impossible

UK: /ɪmˈpɒsəb^əl/ US: /ɪmˈpɑsəbəl/ ,(im pos′ə bəl)

WordReference Random House Learner's Dictionary of American English © 2025

im•pos•si•ble /ɪmˈpɑsəbəl/   adj. 

1. not possible:
   Traveling faster than the speed of light is impossible.
   [It + be + ~ (+ for + object) + to + verb]
   It's impossible (for anything) to travel faster than the speed of light.
2. extremely difficult:
   in the impossible situation of having to increase output, cut workers, and reduce costs.
3. completely impractical:
   an impossible plan.
4. hopelessly unsuitable, undesirable, or objectionable:
   The kids have been impossible all day.

im•pos•si•bil•i•ty /ɪmˌpɑsəˈbɪlɪti/  n. 

[countable] the impossibility of arriving somewhere before you start to go there.

im•pos•si•bly, adv. [before an adjective or adverb]

The jet shot up into the sky impossibly fast.

WordReference Random House Unabridged Dictionary of American English © 2025

im•pos•si•ble  (im pos′ə bəl), adj. 

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.

• Latin impossibilis. See im-², possible
• Middle English 1250–1300

im•pos′si•ble•ness, n. 
im•pos′si•bly, adv. 
Synonyms

• 6. unbearable, intolerable, unmanageable.

Collins Concise English Dictionary © HarperCollins Publishers::

impossible / ɪmˈpɒsəb^əl/ adjective

1. incapable of being done, undertaken, or experienced
2. incapable of occurring or happening
3. absurd or inconceivable; unreasonable
4. intolerable; outrageous: those children are impossible

imˈpossibleness noun

imˈpossibly adverb