Definition of "impossible" in English

adjective

1. Not possible; not able to be done or happen.

   • 13 March 1962, John F. Kennedy, speech at the White House Those who make peaceful revolution impossible will make violent revolution inevitable.
   • It is difficult, if not impossible, to memorize 20,000 consecutive numbers.
   • Sarah thinks that nothing is impossible because things can always somehow happen.

2. (colloquial, of a person) Very difficult to deal with.

   • You never listen to a word I say – you're impossible!
   • This humidity is impossible.

3. (mathematics, dated) imaginary

   • impossible quantities, or imaginary numbers

noun

1. An impossibility.

2. A skateboard trick consisting of a backflip performed in midair.