a weak-kneed person
Contents
软骨头
Pinyin: ruǎn gǔ tóu

Explanation: 比喻意志薄弱、没有骨气的人，甚至丧失气节的人。

Source: 陈残云《山谷风烟》第11章：“想不到此人是个忘恩负义的软骨头，把我出卖了。”

Riddle: 泥鳅的身子

ruǎn gú tou
　　Analogy weak, spineless, or even loss of integrity of the person
Translated by Google
That the soft bone
　　That the bone soft. Common Yiyu no moral integrity. Mao Dun, "Road" Five: "The year was how Yong Han himself. But now young people seem Ruangu Tou."
Translated by Google
English Expression
  1. n.:  a weak-kneed person,  a spineless person
French Expression
  1. n.  celui qui manque de caractère, lâche, poltron
  2. n.  celui qui manque de caractère / lâche / poltron