A pneumatic rill or jackhammer is a portable percussive drill powered by compressed air. It is used to drill rock, break up pavement, among other applications. It works similar to a hammer and chisel, by jabbing with its bit, not rotating it. (A drill driven by compressed air, which rotates its cutting bit is called an air-drill or familiarly, a windy-drill or rotary hammer.) The word jackhammer is used in North American English and in Australia, and pneumatic drill is used colloquially elsewhere in the English speaking world, although (road) breaker is used in the trade.