Inflexibility (9)
I believe the answer is:
rigidness
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">inflexibility</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that inflexibility can be written as rigidness)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for rigidness that I've seen before include "Stiff behaviour" , "property of the firm" , "Unbending quality" .)