to gnaw at sb or to gnaw away at sb
guilt, doubt, fear, feeling +使苦恼；折磨
Guilt gnawed at her for abandoning him.因抛弃他而产生的内疚感让她饱受折磨。
Doubts were already gnawing away at the back of his mind.内心的疑虑早已使他饱受煎熬。
These desires gnaw away at us constantly.这些欲望时常让我们苦恼。