n. 1.〔古语〕石弩。 2.【台球】撞空；【网球】(碰壁)弹回；〔比喻〕间接的一击。 3.(拖炮用的)垫肩。
an engine that provided medieval artillery used during sieges; a heavy war engine for hurling large stones and other missiles 同义词：catapult, arbalest, arbalist, ballista, mangonel, onager, trebuchet, trebucket,