corpsing
n.— «In another featurette the two creators expound on “The Art of Corpsing,” the term for the uncontrollable laughter that, judging by outtakes also included, was epidemic on the show’s set.» —“DVD Review: ‘Extras, Season Two’” by Rick Porter Zap2it July 10, 2007. (source: Double-Tongued Dictionary)
This word has a long-ish tradition in the British entertainment media ; it certainly goes back 50 years , and quite possibly much more .
I am not able to offer a derivation , although historically an actor was often said to have “died on stage”.
A very good example of corpsing on TV can be seen in old Peter Cook & Dudley Moore sketches from , I guess , the first half of the 1960’s .