n.祸根；失败的原因
动词undo的现在分词形式.
Greed was his undoing. 贪婪就是坠落
He was not to know then that this was to prove his undoing. 当时他并不知道，这件事为他种下了祸根。
In the end his ambition was his undoing. 到最后他的野心是他完蛋的原因。
Stress can be the undoing of so many fine players. 紧张可能是这许多优秀选手失败的原因。
That proved to be my undoing, for I soon got back to my old bad habit of dozing off in front of the screen. 这证明了我的失败，因为我不久就回到电视屏幕前打瞌睡的坏习惯去了。
