晚节不保 fail to maintain integrity in old age
Explanation
晚年丧失节操，多指名声和地位的败落。也指事情在即将成功的时候却失败了。
Losing one's moral character in old age, often referring to the downfall of reputation and status. It can also mean that something fails just before it is about to succeed.
Origin Story
一代名相李斯，辅佐秦始皇统一天下，建立了赫赫功勋。然而，他晚年因猜忌韩非，陷害同僚，最终被腰斩，落得个身败名裂的下场，可谓晚节不保。他的一生警示着我们：做人要正直，要坚持自己的原则，不能因为一时的利益而放弃自己的底线，否则，即使曾经功成名就，最终也会落得个悲惨的结局。
Li Si, a famous minister, assisted Qin Shi Huang in unifying China, achieving great merit. However, in his later years, due to jealousy of Han Fei and framing colleagues, he was eventually executed, resulting in a ruined reputation—a clear case of 'wan jie bu bao'. His life serves as a warning: one must be upright, adhere to principles, and not abandon one's bottom line for momentary gain. Otherwise, even with past success, one may ultimately meet a tragic end.
Usage
主要用于评价一个人在晚年时的行为和表现，通常带有负面评价。
Mainly used to evaluate a person's behavior and performance in old age, usually with a negative connotation.
Examples
-
他一生为官清廉，却在晚年贪污受贿，真是晚节不保！
ta yisheng wei guan qinglian,que zai wannian tanwu shouhui,zhen shi wanjie bu bao! gong kui yi kui,wanjie bu bao,ling ren wanxi
He was an honest official all his life, but in his old age he took bribes, and his reputation was ruined!
-
功亏一篑，晚节不保，令人惋惜。
Almost a success, but then it ended badly. How sad to see such wasted potential!