When a subject excretes faeces onto the pectorial bridge of a target, causing the faeces to then "slide" down the torso of the target. This often leaves an invertebrae-like trail running down the targets chest. The Slider is considered successful when it reaches the belly button, and part of the faeces become lodged within it. Sadly this makes it impossible to successfully slider somebody with an outy belly button.
"Did you see that slider? It looks like someone drew a line with brown felt-tip down marks chest."