Rigidly (8)
I believe the answer is:
strictly
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">rigidly</span>' is the definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for strictly that I've seen before include "Rigorously, stringently" , "glam BBC show" , "With no exceptions" , "definitely" , "Rigorously, severely" .)