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?
by A. Burrows April 17, 2007
1 more definition
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!"
by kris B May 16, 2006