Telegraph's lead? (5)
I believe the answer is:
cable
I believe this clue is a double definition.
'telegraph's' is the first definition.
('cable' can be a synonym of 'telegraph')
'lead?' is the second definition.
(thesaurus)
(Other definitions for cable that I've seen before include "Wire, flex" , "Naut. length; transmit" , "Conductor for transmitting electric power" , "Strong thick rope made of twisted hemp or steel wire" , "Telegraph" .)