knee-slapper
knee
-
slapper
https://gyazo.com/f490850ed289d6d01df3377fd5a4e529
noun
North American
informal
an
uproariously
funny
joke
.
〔膝をたたいて笑うほど〕おかしな［大受けの］冗談［ジョーク］
DERIVATIVES
knee-slapping
adjective