Engine resembling a crossbow, used in hurling missles or large arrows. (Gies, Joseph and Francis. Life in a Medieval Castle, 225) Related terms: Bombard / Catapult / Espringale / Mangonel / Springald / Trebuchet
The ballista (Latin, from Greek ballistÄ“s, from ballein 'to throw', plural ballistae) was a powerful ancient crossbow, although employing several loops of twisted skeins to power it using torsion rather than a prod. Early versions ejected heavy darts or spherical stone projectiles of various sizes. It developed into a smaller sniper weapon, the Scorpion.