an engine that provided medieval artillery used during sieges; a heavy war engine for hurling large stones and other missiles | motor that converts thermal energy to mechanical work |
a plaything consisting of a Y-shaped stick with elastic between the arms; used to propel small stones | a wheeled vehicle consisting of a self-propelled engine that is used to draw trains along railway tracks |
a device that launches aircraft from a warship | an instrument or machine that is used in warfare, such as a battering ram, catapult, artillery piece, etc. |
| something used to achieve a purpose |