Thick scarf (7)
I believe the answer is:
muffler
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">thick scarf</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for muffler that I've seen before include "Thick scarf - silencer (US)" , "Kind of scarf" , "Wrap or scarf worn round the neck" , "Sound deadener" , "Warming garment" .)