Barely lit (3)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">barely lit</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for dim that I've seen before include "Not bright, cloudy" , "Badly lit or not so bright" , "Not brilliant" , "progressing towards piano" , "Not bright, shadowy" .)