Wear away by friction (6)
I believe the answer is:
abrade
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">wear away by friction</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 abrade that I've seen before include "Scratch" , "Rub off or scrape away" , "Shave" , "Day breaks? > Start as before" , "Chafe" .)