kackflap 

The act of shimmying one's hips so as to cause the penis to bounce back and forth off of the left and right hip bones.

How funny was it when Esteban dropped his pants at the party and showed everyone his kackflap?

kackflap by A. Burrows April 24, 2007

kackflap 

another word for the skateboarding trick "Kickflip". the trick consists of you ollieing and kicking your front foot so the board does a barral roll type thingg. it is possible to do a double kackflap and sometimes even a tripple kackflap

"man, yesterday i landed a kackflap that was like 3 feet high!"

kackflap by kris B May 24, 2006