impossible

1. impossible (adj) — sense 1

Definition: Not possible; not able to be done or happen.

Example: 13 March 1962, John F. Kennedy, speech at the White House
Those who make peaceful revolution impossible will make violent revolution inevitable.

2. impossible (adj) — sense 2

Definition: Very difficult to deal with.

Example: You never listen to a word I say – you're impossible!

3. impossible (adj) — sense 3

Definition: imaginary

Example: impossible quantities, or imaginary numbers

4. impossible (noun) — sense 4

Definition: An impossibility.

Example: In fact, to most people, the real impossibles do not seem impossible, or wonderful, or even difficult at all.

5. impossible (noun) — sense 5

Definition: A skateboard trick consisting of a backflip performed in midair.