The remains of a cigarette after it has been split open and its contents used to roll a joint (mainly cannabis).
i.e The filter and the bit of white paper that has been licked down one side.
Someone had to come up with a name for it, as it was potentially as incriminating as a pack of king size Rizla, or worse a joint butt, and worse still - your stash of hash !!
The memory of exactly how this came into existence is somewhat hazed, due to being very stoned at the time. Driving through Waltham-Stow in the back of a smokey white Ford Sierra circa 1991 - 1993 comes to mind.
Shit it's the cops !!! hide all the evidence and don't forget the Waltham-skins !!!