Unbending, stiff (5)
I believe the answer is:
rigid
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">unbending</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that unbending can be written as rigid)</span><br/ ><br/ >'<span class="explanation-format__original">stiff</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that stiff can be written as rigid)</span><br/ ><br/ ></span>
(Other definitions for rigid that I've seen before include "Stiff and inflexible" , "Hard" , "Stiff, unmoving" , "unwilling to move" , "strict" .)