Definition: an important moment that decides whether you will succeed or fail
Examples:
Today’s presentation in front of the board is very important. It will decide whether they approve our project and we get promoted, or they kill our project and fire us. It is a make or break moment for us.
This was a very important order, and we messed up the delivery schedule. The customer is very angry. This is a make or break moment. If we handle this well, we’ll keep the customer. If we don’t, we’ll lose him.