(noun, adjective)


1. not capable of occurring or being accomplished or dealt with

- an impossible dream

- an impossible situation

Similar word(s): hopeless, hopeless, impracticable, infeasible, unfeasible, unworkable, out, unachievable, unattainable, undoable, unrealizable, impractical, unrealistic, insurmountable, unsurmountable, unthinkable

2. totally unlikely

Similar word(s): unthinkable, inconceivable, unimaginable

3. (used of persons or their behavior) not acceptable or reasonable

- impossible behavior

Similar word(s): intolerable, unbearable, unendurable, unacceptable

Sentences with impossible as an adjective:

- It is difficult, if not impossible, to memorize 20,000 consecutive numbers.

- Sarah thinks that nothing is impossible because things can always somehow happen.

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

- impossible quantities, or imaginary numbers


1. something that cannot be done

- his assignment verged on the impossible

Definition categories: thought, impossibility