(n) A piece of aluminum foil that is folded in such a way that it can be used as a pipe. In one episode of The Chapelle's Show, Dave Chapelle is seen smoking PCP out of one, but usually they are used to smoke weed. They are normally used when nothing else can be found.
Yo, you got a bowl.
Nothing to smoke out of?
Guess we'll have to use a tinnie.