informal + impolite. —used to say that one thinks that something will never happen I'll apologize when hell freezes over.

What does freeze hell over mean?

phrase [PHRASE after verb] If you say that you will do something until hell freezes over, you are emphasizing that you will do it for a very long time or for ever.

What would happen if hell froze over?

If you say that something will happen when hell freezes over, you mean that it will never happen. Want to learn more? Improve your vocabulary with English Vocabulary in Use from Cambridge. Learn the words you need to communicate with confidence.