cat·a·pult /ˈkætəˌpʌlt, ˌpʊlt/
  發射機,彈弓,投石器(vt.)發射
  Cat·a·pult n.
  1. Mil. Antiq. An engine somewhat resembling a massive crossbow, used by the ancient Greeks and Romans for throwing stones, arrows, spears, etc.
  2. A forked stick with elastic band for throwing small stones, etc.
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  catapult
       n 1: a plaything consisting of a Y-shaped stick with elastic
            between the arms; used to propel small stones [syn: slingshot,
             sling]
       2: a device that launches aircraft from a warship [syn: launcher]
       3: medieval artillery used during sieges; a heavy war engine
          for hurling large stones and other missiles [syn: arbalest,
           arbalist, ballista, bricole, mangonel, onager,
          trebuchet, trebucket]
       v 1: shoot forth or launch, as if from a catapult; "the enemy
            catapulted rocks towards the fort"
       2: hurl as if with a sling [syn: sling]