Strengthened (6)
I believe the answer is:
braced
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">strengthened</span>' is the definition.<br/ ><span class="explanation-format__explanation">(bracing is a kind of strengthening)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for braced that I've seen before include "Supported, gave firmness to" , "Prepared for a setback" , "Steadied against a blow or shock" , "Stiff" , "Ready for action" .)