Report from south London, say, sent over (4)
I believe the answer is:
news
'report' is the definition.
(synonyms)
'south london say sent over' is the wordplay.
'south' becomes 's' (abbreviation).
'london say' becomes 'wen' (wen could historically mean a large city).
'sent over' shows that the letters should be reversed in order.
's'+'wen'='swen'
'swen' backwards is 'NEWS'.
'from' acts as a link.
(Other definitions for news that I've seen before include "Information about recent events" , "Intelligence, information" , "Information disseminated by the media" , "Sewn (anag.)" , "Reports of recent events" .)