Eaten away (6)
I believe the answer is:
eroded
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">eaten away</span>' is the definition.<br/ ><span class="explanation-format__explanation">('erode' can be a synonym of 'eat away')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for eroded that I've seen before include "Wore away" , "Worn away by weather or water" , "Eaten away" , "Worn away by time, wind or water" , "Worn away, ground down" .)