A Broken reed

• n. 不可靠的人(物)

a broken reed的用法和样例：

例句

1. In her intemperate husband, Mrs Fang has a broken reed.
   有了一个酗酒的丈夫，方太太依靠无人。
2. He let me down at the last minute and turned out to be a broken reed.
   他在紧急关头拆了我的台，成了背信弃义的人。