1 an occasion when something that was joined together or united breaks into separate parts: --
The story depicts the crack-up of the writers' own partnership.
The empire became ungovernable, resulting in a total crack-up.
He had what he calls a "crack-up" when he was a young journalist.
2 someone or something that is very funny: --
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
We kunnen het stap voor stap voltooien, hoe lang de weg ook is en het kan niet worden voltooid, hoe kort de weg ook is, als je niet eens je voetafdruk markeert.