knee-slapper

something really funny (from the slapping of the knees and hitting the floor associated with laughter.

That was one heck of a knee-slapper.

by The Return of Light Joker September 27, 2008

Knee Slapper slong

A knee slapper slong is a penis long enough to slap against a man's knee.

Jaime is endowed with a knee slapper slong!

by I, Wreckerrr October 13, 2016

knee slapper

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

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

Peggy Sue called me a Knee Slapper instead of a dick today.

by Springloaded June 6, 2004

Knee-Slapper

/nē/ /slapper/

Noun

1. A joke; typically a pun or otherwise regarded “Dad-Joke”, the humour of which prompts an audible slap-of-the-knee from one or more of the parties involved.

Ron: “So me and the wife were down in Mexico last month, and she twisted her ankle at Salsa Night”.

Gord: “Oh no, what did you do?”

Ron: “I called ‘Nine-Juan-Juan’”.

*Audible laughter and slapping-of-the-knee*

Gord: “Jesus Murphy, Ron, you really had me going there for a second. Now that’s a Knee-Slapper”.

by be4nz1111 August 20, 2023

Knee Slapper

A saying a person does when another person says an unfunny joke but you're being sarcastic about it, indicating it was the funniest joke you have ever heard in your life. (being sarcastic if you didn't get that)

"Hey Billy, why did the chicken cross the road?... TO GET TO THE OTHER SIDE!" *laughs hysterically*

"What a knee slapper, Timmy!" *slaps knee*

by lovelyleftorgan777 May 4, 2022

Knee-slapper

When you cut your knees off and slap your partner with them

I was having a bad so my husband gave me a knee-slapper

by Unifart April 2, 2021

Double Knee Slapper

A double knee slapper is when you hear something that is so funny that it brings out your embarrassing loud obnoxious laugh. So instead you fake laugh out loud and jump in the air, slapping both your knees going “Boop boop” then land on your feet, yelling “Thats a Double Knee Slapper!”

Dude, Dom’s Double Knee Slapper yesterday reacting to her joke, nearly made me piss myself.

by DomTheItalian November 26, 2017