Barnaby's rude about golf (5)
I believe the answer is:
rudge
'barnaby's' is the definition.
(Barnaby Rudge is a Dickens novel)
'rude about golf' is the wordplay.
'about' is an insertion indicator.
'golf' becomes 'g' (phonetic alphabet: alpha, bravo, charlie etc.).
'rude' enclosing 'g' is 'RUDGE'.
(Other definitions for rudge that I've seen before include "Dickens character" , "'Barnaby - - ' by Charles Dickens" , "Dickens novel 'Barnaby .....'" , "Dickensian halfwit" , "Dickensian character" .)