knee slapper 

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.

Comedian: I just flew in from Los Angeles, and boy are my arms tired!

Audience member in sarcastic tone: wow that's a real knee-slapper

knee slapper by Joe February 11, 2003

knee slapper 

something that is stupid and funny at the same time

Guy 1: So a guy walks into a bar...OUCH!
Guy 2: ROFL THAT'S A KNEE SLAPPER! *slaps knee*
Random Guy: Oh yeah? How bout a face slapper! *slaps Guy 1 and 2's face*

knee slapper by Skullex May 18, 2008

Knee slapper 

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".

What do you call someone who doesn't fart in public?

A private tutor!!

-knee slapper

Knee slapper by MegDar September 20, 2009

Knee Slapper 

Sumthing very funny and ridiculous

Thats humungous.....
Thats Wat She SAid

ROFL THATS A KNEE SLAPPER!!!

Knee Slapper by SALKFJsalfk February 17, 2008

Knee Slapper 

When someones penis is so big that it slaps the inside of their knees when they walk.

What size condom would you like?

Let's just say it's a knee slapper.

Knee Slapper by Erak22 September 27, 2009

knee slapper 

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

We's burnin knee slappers in this bitch.

knee slapper by The Pizza Man April 20, 2006

Knee Slapper 

1) An otherwise unfunny, awkward, or just stupid joke. Usually a dad pun or something of the sort. Said after this to show that it should have never been said in the first place. Invented by hillbillies and rednecks when sitting on their porches, slapping their knees when somthing funny happens.


2)said after something funny and stupid happens.

1)
dumb guy:"Two peanuts are walking down the street, and one of them was assaulted!"

normal guy (slaps knee and fake-laughs):"Wow! That sure was a knee slapper!"



2)
guy skates and falls off rail, hurting his knee and friend laughs.
Later they are talking and laughing about a dumb joke.

friend:"wow that sure was a knee slapper!" (slaps knee)

skating
guy:"yea!"(slaps knee very hard, and dislocates it from the earlier accident)

friend:"no that's a knee slapper!"

Knee Slapper by dhawk123 March 8, 2009