Strong thick rope (5)
I believe the answer is:
cable
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">strong thick 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 cable that I've seen before include "Strong line" , "Heavy chain or rope" , "Rope for communication" , "Communications wire" , "Naut. length; transmit" .)