Adjective : sidesplitting laughter. ,sidesplitting farce.    From Dictionary.com. 

How sidesplittingly funny and original you all are!.    From Wordnik.com.  [Hillary Celebrates Birthday With $1.5 Million Fundraiser] Reference

I also started the sidesplittingly funny Aquanatal classes.    From Wordnik.com.  [Turncoat] Reference

I don't know about any of my readers, but I find that concept sidesplittingly funny!.    From Wordnik.com.  [Time for a new Look?] Reference

At the same time, their print counterparts created sidesplittingly entertaining books, magazine articles, newpaper columns, plays etc.    From Wordnik.com.  [Pity the left, they aren't funny anymore] Reference

I can't get enough of the sidesplittingly funny and charming Charlaine Harris and Margaret Maron - I really could follow them around to just to hear them talk.    From Wordnik.com.  [For a Good Time...] Reference

Speaking of which, it seems the writer probably had a bit of a brainstorm during the creative process, and said to himself, You know what's really sidesplittingly funny?.    From Wordnik.com.  [Crank] Reference

JakeandAmir.com (5) The Setup: Real-life CollegeHumor.com employees Jake Hurwitz and Amir Blumenfeld turn the cameras toward their desks, chronicling their sidesplittingly dysfunctional, partially fictional work relationship.    From Wordnik.com.  [The Web-to-TV Stars Human Giant Predict the Next Web-to-TV Stars] Reference

What reading it might not convey is how sidesplittingly funny it can be - I read it more than a year before seeing it and loved it both times, but didn't really laugh when I read it; on stage, it's hilarious, always keeping the edge of the knife to the throat at the same time.    From Wordnik.com.  [The Pillowman] Reference

But while Osbourne's memoir is sometimes painful to read, it's also sidesplittingly funny.    From Wordnik.com.  [Postbulletin.com Local News] Reference

It seemed like every other minute, some minions will wander into frame to do something sidesplittingly funny.    From Wordnik.com.  [SARA - Southeast Asian RSS Aggregator] Reference

Humor that's sidesplittingly, disgustingly (in a good way), and sometimes sentimentally (bordering on sappy) honest.    From Wordnik.com.  [Film.com Movie Blog] Reference

There are dozens of moments like this in the movie and they are sidesplittingly funny for people who have a sense of humor and are not pretending to be pious.    From Wordnik.com.  [Epinions Recent Content for Home] Reference

Another person classed apparently by the cops as one to watch (at least, the cops of some years ago) is the sidesplittingly funny campaigner-comedian Mark Thomas, who said he had been best mates with the possibly traitorous Hogbin.    From Wordnik.com.  [The Register] Reference

A celebrity ambush interview show, is sidesplittingly funny, if you think embarrassment is a good time.    From Wordnik.com.  [ABQnews Seeker Front Page] Reference

Apparently he was convinced that his line about day care was so sidesplittingly funny that it was worth repeating, so rather than risk having him say it again, I simply nodded, thanked him, and went over to Deborah’s car.    From Wordnik.com.  [Dexter in the Dark]

I want Romney to explain exactly how his Mormonism influenced his various votes on abortion, stem cell research, and access to birth control, and, if his answer is anything other than “it’s totally irrelevant”, why exactly we should take seriously as a presidential candidate someone whose policy decisions are grounded in such absolute, sidesplittingly ludicrous inanity as the Book of Mormon.    From Wordnik.com.  [2007 June 25 « Lean Left] Reference

Clinton is sidesplittingly and achingly funny.    From Wordnik.com.  [June 2008: More letters to the editor] Reference