Something so hilarious it makes u slap your knees. Funny moments that cause uncontrollable laughter.
My niece and I seen a man with a car dealership flag on his bicycle chased by a bunch of Chihuahuas, it was such a knee-slapper!! Hahahaha
by MainRain October 13, 2018

When your girl pours cinnamon (or any various other spices) all over your cock and balls and proceeds to slap the fuck out of your burning genitalia.
by Homo shitdick July 4, 2025

A sex maneuver where a man's penis is covered in at least two different lubricants then inserted in a woman's anus then vagina. Once in the vagina the wee wee schnitzel is slapped around often making funny noises.
Michael: "Hey man, how'd it go with Stacy last night?"
James: "Went pretty damn good, gave her the ol' triple dipple fudge dipped salmon slapper."
Michael: "Damn bro, that's a pro move."
James: "Went pretty damn good, gave her the ol' triple dipple fudge dipped salmon slapper."
Michael: "Damn bro, that's a pro move."
by Daddy drerek drekson November 17, 2020

Girl who spends her time hanging around in carparks whether its in her boyfriends car or her own...thinking she is it...
by lilginga June 17, 2012

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*
"What a knee slapper, Timmy!" *slaps knee*
by lovelyleftorgan777 May 4, 2022

by Daddyaddy1219 July 30, 2021

The 'Macca Slapper' is a unique technique which is hard to master. Founded by the great Macca Slapper himself, you must thrust your junk up and down creating a clapping effect from your nut sack and penis slapping against your skin. This technique is for men only.
My boyfriend can do the Macca Slapper, he is way better than yours!
My Macca Slapper sound makes the whole room vibrate.
My Macca Slapper sound makes the whole room vibrate.
by Yatü August 27, 2018
