look up any word, like fleek:
 
1.
A Parkour movement in which the traceur plants his hands on a rail or obstacle and leaps over it, turning his body 180 degrees to end up in a reversed hanging position.

This move can be used to slow down before attempting a large drop or cat leap.
Good Tutorial of a Turn Vault by Ozzi:

http://www.youtube.com/watch?v=965PnBre_SA
by dick traceur July 25, 2008