What Is The Opposite Of Completely Impossible

What is the opposite of completely impossible?

Insurmountably difficult: regarded as impossible to be done, achieved, or fulfilled.If you say something is unlikely to happen or unlikely to be true, it means you have some degree of confidence that it won’t happen or isn’t true. The likelihood of a military coup is low. You probably won’t be aware of it, as with many technological revolutions. Unlikely to occur or be true.

What idiom for “impossible to happen” is there?

What It Means When Pigs Fly. When pigs fly is a figure of speech that means something is not possible. One could respond with a literal statement to the effect when someone says they want to do something that is simply impossible. It is impossible for pigs to fly, and that is exactly what the expression means. When someone says something that we believe to be impossible or extremely unlikely, we respond by saying this.