crack up

/ˈkɹæk ˈʌp/verb
RareNot in standard dictionaries
1

To laugh heartily.

2

To cause to laugh heartily.

3

To tease (someone) or tell jokes at the expense of (someone).

4

To become insane; to suffer a mental breakdown.

5

To break down or fall apart; to stop functioning; to shatter.

6

To separate a group.

7

To crash an aircraft or automobile.

8

To remove the shell from nuts.

9

To crack (petroleum). (to break down (a complex molecule), especially with the application of heat: to pyrolyse)

10

To praise or applaud (something); to promote a positive view of (something).

#dated#informal#slang