Playing Garth Peel in The Wire (9)
I believe the answer is:
telegraph
'wire' is the definition.
(telegraph wire is a kind of wire)
'playing garth peel' is the wordplay.
'playing' indicates anagramming the letters.
'garth'+'peel'='garthpeel'
'garthpeel' with letters rearranged gives 'TELEGRAPH'.
'in the' acts as a link.
(Other definitions for telegraph that I've seen before include "Electrical transmission of coded signals" , "Send message" , "It's used for communications over wires" , "Daily" , "give advance notice" .)