Inured (8)
I believe the answer is:
hardened
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">inured</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that inured can be written as hardened)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for hardened that I've seen before include "Inured" , "Toughened" , "Became obdurate" , "Tough, cynical" , "Experienced, tough" .)