There are many synonyms for the phrase "fall about", which basically means to laugh uncontrollably. Some of the more common synonyms include "crack up", "roar with laughter", "burst out laughing", "guffaw", "double over", and "have hysterics". Other related phrases include "rolling on the floor laughing", "in stitches", "falling apart with laughter", and "laughing until you cry". No matter which synonym you use, falling about is a great way to release stress and enjoy life. So go ahead and find something hilarious to laugh about today!