crack up
phrasal verbcrack up (informal)
- to become ill, either physically or mentally, because of pressure
- You'll crack up if you carry on working like this.
- He thought he'd never get through the ordeal without cracking up.
- to start laughing a lot
- He walked in and everyone just cracked up.
crack somebody up
- (informal) to make somebody laugh a lot
- Gill's so funny —she just cracks me up.