Senseless row on the phone with Charlie (9)
I believe the answer is:
numbskull
'charlie' is the definition.
(I know that charlie can be written as numbskull)
'senseless row on the phone' is the wordplay.
'senseless' becomes 'numb' (I've seen this in another clue).
'row' becomes 'scull' (to scull is to row a boat with sculls).
'on the phone' shows a homophone (sound like).
'scull' is a homophone of 'skull'.
'numb'+'skull'='NUMBSKULL'
'with' acts as a link.
(Other definitions for numbskull that I've seen before include "Fool" , "of limited intelligence" , "Idiot" , "Blockhead, bonehead" , "Stupid person" .)