Bent peg later attached to high wire (9)
I believe the answer is:
telegraph
'wire' is the definition.
(I know that wire can be written as telegraph)
'bent peg later attached to high' is the wordplay.
'bent' is an anagram indicator.
'attached to' says to put letters next to each other.
'high' becomes 'h' (abbreviation).
'peg'+'later'='peglater'
'peglater' is an anagram of 'telegrap'.
'telegrap'+'h'='TELEGRAPH'
(Other definitions for telegraph that I've seen before include "give advance notice" , "It's used for communications over wires" , "A scoreboard" , "Signal" , "Daily" .)