IMPOSSIBLE

[adjective] [not gradable] - unable to exist, happen or be achieved; not possible (ACHIEVABLE)She ate three plates of spaghetti and a piece of cake? That's impossible. I don't believe it!It seems to be impossible to find a decent tailor these days.It seems impossible that I could have walked by and not noticed her.He made it impossible for me to say no.A situation might be described as impossible if is extremely difficult and there does not seem to be a solution.It's an impossible situation - she's got to leave him but she can't bear losing her children.A person might be described as impossible if they are extremely difficult to deal with or are behaving badly.I had to leave the job because my boss was impossible.My niece gets impossible when she's tired - you can't do anything to please her.