Radio presenter’s formal jacket spoken of (6)
I believe the answer is:
deejay
'radio presenter's' is the definition.
(I've seen this before)
'formal jacket spoken of' is the wordplay.
'formal jacket' becomes 'dj' (abbreviation for dinner jacket).
'spoken of' shows a homophone (sound like).
'dj' sounds like 'DEEJAY'.
(Other definitions for deejay that I've seen before include "Record-spinner" , "Player of records" , "Radio presenter" , "Informal disc jockey" , "Radio disc man" .)