Pugilist's complaint about shoulder, essentially — I'm afraid of boxing shame? (11,3)
I believe the answer is:
cauliflower ear
'pugilist's complaint' is the definition.
(a boxer or pugilist may have a cauliflower ear)
'about shoulder essentially i'm afraid of boxing shame?' is the wordplay.
'about' becomes 'ca' (short for circa).
'essentially' indicates the central letters.
'i'm afraid of' becomes 'I fear' (to fear something is to be afraid of it).
'boxing' is an insertion indicator ('box' can mean contain, as in to put in a box).
'shame?' becomes 'lower' (shame can mean to lower or demean).
The centre of 'shoulder' is 'ul'.
'ifear' enclosing 'lower' is 'iflowerear'.
'ca'+'ul'+'iflowerear'='CAULIFLOWER EAR'
(Other definitions for cauliflower ear that I've seen before include "Damaged organ" , "result of being battered?" , "damaged appendage" , "Auricular deformation seen in boxers and rugby forwards?" , "Battle-scarred lug" .)