chī yī qiàn, zhǎng yī zhì
吃 一 堑， 长 一 智

A fall in pit, a gain in your wit.

解释 ( paraphrase )
这条谚语告诉我们：一个人受到一次挫折以后，如果总结经验教训，就能增长见识和智慧。

This proverb’s message is: Having gone through a setback, one will have gained experience and wisdom, which will be useful if only one can take warning and learn something from the setback.

吃： 在这里有遭受，经受的意思。
        Here 吃 means to suffer, to experience.
 

堑(qiàn): 是隔断交通的沟，引申为挫折。
             A ditch which cuts off traffic; here, by extension, it means a setback.

同义词 ( synonym )
不经一事，不长一智

造句 ( example )
吃一次亏,就要“吃一堑长一智”。