n.活塞；跳水的人；马桶搋子
The plunger is clamped into the crosshead. 活塞与滑块相连接。
The plunger should be withdrawn from sleeve. 柱塞应从套筒里抽出来。
He took a photo of the plunger in action. 跳水者正在跳水时, 他拍了张快照。
