Paling (6)
I believe the answer is:
fading
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">paling</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for fading that I've seen before include "Evanescing" , "Disappearing gradually" , "Losing colour gradually" , "Growing fainter" , "Weakening in force or intensity" .)