Most desolate (8)
I believe the answer is:
bleakest
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">most desolate</span>' is the definition.<br/ ><span class="explanation-format__explanation">('bleak' can be a synonym of 'desolate')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for bleakest that I've seen before include "Most stark" , "Most dismal and desolate" .)