The smallest unit of currency in Ankh-Morpork. It is worth one-sixteenth of a penny. An indication of just exactly why the Royal Mint is in trouble can be gleaned from the fact that it costs one shilling to make an elim coin, because of all the fine fiddly detail that needs to be engraved onto it. (The manufacture of each coin costs one hundred and ninety-two times its face value)
On reputable report, it may be exchanged in certain places for a cigarette end (partially smoked), a half-consumed apple core, or a very small potato that hasn't gone all that green yet.