Chip away at (5)
I believe the answer is:
erode
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">chip away at</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for erode that I've seen before include "'Deteriorate, wear away (5)'" , "Grind down" , "Become ground down or deteriorate" , "Wear away with weather" , "Gradually destroy" .)