coup de grace

基本解释

The coup de grace is Cantor’s proof that some infinite sets are bigger than this.
这个论题是康托的杀手锏，他用它来证明某些无限集要比这个无限集大。
Adding a new twist to the tale, the latestresearch shows that the fungal coup de grace usually occurs at solar noon, whenthe sun is at its strongest.
这个故事又增加了一个新的进展，最新的研究表明真菌的致命一击发生在正午，即阳光最强烈的时刻。
When he had completed theexcision, and had taken his souvenir, he administered the coup de grace: asingle deep slash across the neck, from left to right.
他完成切除，拿走纪念品之后，实施了最后的致命一击：整个颈部从左向右，深深的一刀。

And then he hears the coup de grace, it's the shots, one after another, and then he sees a priest staggering out, overwhelmed by it all, and then he moves onto something else.
接下来他就听见了那致命的声响,枪声,一声接着一声,之后他看见惊魂未定的牧师踉跄而出,然后他就调转笔锋写其它事情去了
耶鲁公开课 - 1871年后的法国课程节选

In the end, it will probably be Mr Aso's mediocre performance that administers the coup de grace.
ECONOMIST: The ruling LDP plays a sloppy endgame

A coup de grace is an action or event which finally destroys something, for example, an institution, which has been gradually growing weaker.