Literal translation
to make oneself a bundle of laughter
Meaning
to have a good laugh
Explanation
A fourro, literally, is a stuffed cold cut, a symbol of a good meal: people used to say si faire uno fourro for "to have a hearty meal". The expression shifted toward uno fourro de rire, "a hearty laugh", all the more so since good meals are often the occasion for much laughter. The original meaning of fourro is now largely forgotten, even in Provençal where it has fallen out of use, but it survives in this phrase. The image echoes laughing until one's embouligue or bédélet bursts.