Heavy cable? (4)
I believe the answer is:
lead
This clue is a double definition.
'heavy' is the first definition.
(thesaurus)
'cable?' is the second definition.
(thesaurus)
(Other definitions for lead that I've seen before include "First news item" , "Command; metal" , "Soft, heavy metal" , "Metal; clue" , "Go in front with heavy metal" .)