Define Knee Slapper Meaning

Sarcastically used to point out an unfunny joke. It originates from the act of slapping one's knee during vigorous laughter. Later took on a sarcastic meaning.

something that is stupid and funny at the same time

A blunt that is so large, or otherwise so potent, a hit causes you to slap your knee and say "GAH'DAM."

From (Or inspired from) The Tom Green song "Pet names for Genitalia"

A penis.
Because it slaps your knees, if you're horribly unproportioned.

when someone slapps their knees because somethings really funny.

a joke that is so silly that in order to handle it you must slap your knee

A funny story or event. Generally used facetiously. If not used facetiously, the user is a dork.

A group of nine friends who make weird jokes and react to them by saying "that's a knee slapper, har de har har" and slapping their knees.

adverb. A term used to describe a dumb-ass joke. Its inception was the result of someone noticing their friend slapping their thigh/knee when a joke was told. It's an official "knee slapper" when the person laughing sqints their eyes, slaps their knee, and can barely speak due the amount of laughimg taking place. This definition is considered a "knee slapper".

Sumthing very funny and ridiculous