A stunt that was really stupid
OR a person who is costantly acting stupid
OR the host of Jackass
1.*guy skateboards off the top of his 2 story house and lands on a trampoline only for the skateboard to hit him in the nuts* "DUDE, THAT WAS SOOOO JOHNNY KNOXVILLE!"
2."Greg is such a Johnny Knoxville."
3."Did You see what Johnny Knoxville did on Jackass?"
A johnny Knoxville is a beer pong re-rack formation involving 5 cups. It is the standard diamond formation with the extra cup in the front on the left or right side (the extra cup is touching two of the front three cups). This is called a Johnny Knoxville after his character in Men In Black, were he has an extra head. This originated in Long Beach cerca 2007.
After sinking the fifth cup in a beer pong game, "Hey can we get a Johnny Knoxville for our first re-rack."