Unlit (4)

I believe the answer is:
dark
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">unlit</span>' is the definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for dark that I've seen before include "Secret, shadowed" , "sinister and > bleak" , "Black, perhaps - night" , "Unlit" , "Dismal" .)