crack up
US /kræk ʌp/
UK /kræk ʌp/
1.
to laugh uncontrollably or to cause someone to laugh uncontrollably
:
•
The comedian's joke made everyone crack up.
•
I always crack up when I watch that movie.
2.
to suffer a mental or physical breakdown
:
•
The pressure of the job caused him to crack up.
•
She was afraid she would crack up under the stress.