eat away at

From eat away +‎ at.

eat away at (third-person singular simple present eats away at, present participle eating away at, simple past ate away at, past participle eaten away at)

1. (transitive) To erode.

   The river is eating away at the river bank.

2. (transitive) To consume or use up, erode or wear away gradually.

   The expenses ate away at our profits.

3. (transitive) To cause to feel uneasy, troubled, worried, guilty, or vexed; to bother about something.

   Not confessing that I had stolen the money ate away at me until I could no longer sleep.