Thick rope (5)
'thick rope' is the definition.
(cable can mean a rope or wire)
This is all the clue.
(Other definitions for cable that I've seen before include "Hawser, wire" , "Conductor for transmitting electric power" , "Wire; message" , "Communications wire" , "Rope for communication" .)
(Other definitions for hawser that I've seen before include "Large heavy rope" , "tower" , "Heavy rope for nautical use" , "Heavy cable for securing ships" , "Thick mooring rope" .)