The large suspect holding piano wire (9)
I believe the answer is:
telegraph
'wire' is the definition.
(I know that wire can be written as telegraph)
'the large suspect holding piano' is the wordplay.
'suspect' indicates anagramming the letters (a suspicious or unusual spelling).
'holding' indicates putting letters inside.
'piano' becomes 'p' (musical abbreviation).
'the'+'large'='thelarge'
'thelarge' is an anagram of 'telegrah'.
'telegrah' enclosing 'p' is 'TELEGRAPH'.
(Other definitions for telegraph that I've seen before include "Transmission (by wire on poles)" , "System of communication over wires" , "Means of communication" , "A scoreboard" , "It's used for communications over wires" .)