Crack Up American idiom informal
If someone cracks up, he or she starts laughing out of nowhere.
I am surprised that Martin cracked up when I told him jokes today. He had never got my jokes before.
To undergo an emotional stress due to pressure.
I think she is cracking up. Would you believe that she worked for 13 hours yesterday with no break?
To laugh a lot at someone or something
To make someone understand how serious, difficult, or dangerous something is
Laugh in an uncontrollable way
1. To laugh with shyness and embarrassment
2. Used to say that someone vomits on the floor, whether it's carpeted or not
Used to describe someone that gives joy and humor to others
This American idiom is believed to come from the 1600s. At that time, women used to apply a thick layer of makeup on their faces, so whenever they laughed, it would crack up and appear flaky.