side-splitting 
adjective informal
Extremely amusing: side-splitting anecdotes...
- Ths show, of course, was precisely what one would expect - hilarious, side-splitting, laugh-out loud funny.
- Despite the laughs though, many might not find it as side-splitting as the first hilarious instalment.
- With all of that being said, I believe it was about three and half minutes into the film that I realized that The Iron Ladies was going to be one of the most entertaining, side-splitting movies that I would have watched in a long, long time.
Synonyms
hilarious, extremely amusing, very funny, very humorous, comic, riotous, uproarious, screamingly/hysterically funny, too funny for words, rib-tickling, comical, absurd, ridiculous
informal a scream, a hoot, priceless
dated killing, killingly funny
Derivatives
side-splittingly
- Sharp, side-splittingly funny and shockingly sad, the book was snapped up by Hollywood immediately.
- From his side-splittingly amusing brother and uncle, to his newfound Mexican friend Pedro, these characters are so weird, pathetic, likeable and quotable that you'll still be laughing at them long after the movie has ended.
- While not always side-splittingly funny, her delivery is genuine and her stories relevant.