impossible ***
inconceivable
out of the question
unimaginable

To turn back was out of the question for the city.

At the moment a film seems out of the question.

By then other problems will have hit to make growth out of the question.

But out of the question comes the answer, so to speak.

With science by our side, nothing seemed out of the question.

Being seen as anything less than perfect was out of the question.

But making love to her now was out of the question.

Anything more was out of the question, but she wouldn't give him a good answer as to why.

He says that going to his mother was out of the question.

To be made to give her money as well was out of the question for him.