knee slapper

Noun

idiomatic

(idiomatic) A joke, especially one which strikes the listener or reader as particularly humorous.

Japanese Meaning

とても面白い冗談、特に聞いたり読んだりして非常に笑わせる冗談

When Grandpa told that story at the reunion, it was a real knee slapper and had everyone in stitches.

祖父が同窓会でその話をしたとき、それは本当に抱腹絶倒のジョークで、皆を大笑いさせた。

Sense（1）

(idiomatic) A joke, especially one which strikes the listener or reader as particularly humorous.

knee slappers

（ plural ）