Corrodes (5)
I believe the answer is:
rusts
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">corrodes</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know this)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for rusts that I've seen before include "How iron corrodes" , "Oxidises" .)