“适得其反”，汉语成语，意思是恰恰得到与预期相反的结果（The result was just the opposite.）。可以翻译为“run counter to one's desire或have an exactly opposite effect”。

例句：

其结果必然不会像他们所想得那样，而只能适得其反。

The result will definitely turn out to be just the opposite of their wish.

总统的策略可能会适得其反。

The president's tactics could backfire.