Fine strand or yarn (6)
I believe the answer is:
thread
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">fine strand</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">yarn</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ ></span>
(Other definitions for thread that I've seen before include "Yarn, string" , "Strand of, eg, cotton" , "Dearth (anag)" , "Strand of cotton or other fibre" , "What sewer takes" .)