Muffled, subdued (5)
I believe the answer is:
muted
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">muffled</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that muffled can be written as muted)</span><br/ ><br/ >'<span class="explanation-format__original">subdued</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(both can mean restrained or subtle)</span><br/ ><br/ ></span>
(Other definitions for muted that I've seen before include "In music, with sound deadened or muffled" , "low-key" , "Hushed or stifled" , "Of great weight" , "Softened (of sound or colour)" .)