The phrase "eat away" refers to the gradual destruction or deterioration of something. When something is slowly being consumed or eroded, it can be described as "eating away." However, there are several other words or phrases that can be used to convey a similar meaning. "Gradually deteriorate," "erode," "wear away," "corrode," and "diminish" are all synonyms for "eat away." These words can be used interchangeably depending on the context. It is important to use appropriate synonyms to communicate effectively and get the desired message across clearly.