Electric cable (4)
I believe the answer is:
flex
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">electric cable</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for flex that I've seen before include "Contract (a muscle)" , "Bend; insulated cable" , "Insulated wire cable" , "Bendable cord" , "Tighten - bend" .)