a tack for attaching papers to a bulletin board or drawing board
同义词：thumbtack, drawing pin
pushpin详细解释
push.pin n.（名词）A tacklike pin with a large head that is easily inserted into a wall or board.图钉：平头钉状的钉子，有一个大的钉帽，它能很容易地被钉进墙或板中Games A game played by children with pins.【游戏】 针戏：小孩玩的弹图钉游戏
