Thin rope (4)
I believe the answer is:
cord
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">thin rope</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 cord that I've seen before include "Rope; fabric" , "A measure of cut wood" , "Thin string" , "Small rope or thick string" , "Small rope; flex" .)