Definition of "crack up" in English

Verb

To laugh. To laugh heartily.
- It was hilarious. We were cracking up the whole time.
- The joke about the nuns in the bath cracked me up.
- He's always cracking up at me about that.
To laugh heartily.
- It was hilarious. We were cracking up the whole time.
To cause to laugh heartily.
- The joke about the nuns in the bath cracked me up.
To tease (someone) or tell jokes at the expense of (someone).
- He's always cracking up at me about that.
To break. To become insane; to suffer a mental breakdown.
- She got through the war, but cracked up when her sister died.
- The university was really cracking up, losing faculty, students and donors, and it seemed like to go under.
- My motorcycle cracked up before I arrived.
- I have to crack up that little clique.
- We can send you a hundred pounds a month of pecans to crack up.
- The refinery cracks up the heavier oils.
To become insane; to suffer a mental breakdown.
- She got through the war, but cracked up when her sister died.
To break down or fall apart; to stop functioning; to shatter.
- The university was really cracking up, losing faculty, students and donors, and it seemed like to go under.
- My motorcycle cracked up before I arrived.
To separate a group.
- I have to crack up that little clique.
To crash an aircraft or automobile.
To remove the shell from nuts.
- We can send you a hundred pounds a month of pecans to crack up.
To crack (petroleum). (to break down (a complex molecule), especially with the application of heat: to pyrolyse)
- The refinery cracks up the heavier oils.
To affect the image of something. To praise or applaud (something); to promote a positive view of (something).
- She wasn't as impressive as Katie cracked her up.
- Those who have been cracking up the agricultural industry will hopefully reconsider their denigration of it.
- This new computer system is not what it was cracked up to be.
To praise or applaud (something); to promote a positive view of (something).