knee-slapper
noun North American informal
An uproariously funny joke.We had many scenes that were not knee-slappers, but in between takes he would have me laughing so hard that I could relax....
- Though this could easily be the elaborate set up for one of your dad's dinner-table knee-slappers, this is the true-to-life plot of a theatrical venture called Oh No, A Condo!
- There are plenty of smiles and quite a few knee-slappers.
Derivatives
knee-slapping
- At this point, the entire kitchen erupted in knee-slapping laughter.
- What follows is a rare thing: a masterful Shakespearean spin-off - smart, fast moving, and littered with knee-slapping references to the original.
- And despite the fact that there are lots of chuckles in The Ladykillers, there is nothing new or hilarious enough to inspire a knee-slapping good time.