To impale something on a pointed object means to cause the point to go into it or through it.
例句
Researchers observed one bird impale a rodent on a cactus...研究人员观察到一只鸟把一只啮齿动物钉在一棵仙人掌上。Lenny swayed for a moment, then dropped to the ground, impaling himself on his switchblade...伦尼晃了一下,然后倒在了地上,他的弹簧刀刺穿了自己的身体。
英汉词典释义
vt.
钉在尖桩上
He fell out of the window and was impaled on the iron railings.他从窗口跌下去, 身体被铁栏杆刺穿了。