Sidesplitting is a word that is commonly used to describe something that is extremely funny or amusing. However, there are several other words that can be used to convey the same meaning. Some synonyms for sidesplitting include hysterical, rib-tickling, uproarious, belly-laughing, and knee-slapping. Each of these words can be used to describe something that is exceedingly funny, such as a joke, story, or performance. Other words that can be used in place of sidesplitting include hilarious, comedic, amusing, and entertaining. No matter which synonym is used, the underlying meaning is the same - something that is so funny that it makes you laugh uncontrollably.