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knee–slapper

1 ENTRIES FOUND:
knee–slapper /ˈniːˌslæpɚ/ noun
plural knee–slappers
knee–slapper
/ˈniːˌslæpɚ/
noun
plural knee–slappers
Britannica Dictionary definition of KNEE–SLAPPER
[count] US, informal
: a very funny joke or story