Going on about a drink on the Riviera? (7)
I believe the answer is:
leaving
'going' is the definition.
(I know that going can be written as leaving)
'on about a drink on the riviera?' is the wordplay.
'on' becomes 'leg' (cricket term, fielding positions).
'about' is an insertion indicator.
'drink on the riviera?' becomes 'vin' ('wine' in French).
'a'+'vin'='avin'
'leg' placed around 'avin' is 'LEAVING'.
(Other definitions for leaving that I've seen before include "Going away" , "Abandoning" , "Departure" , "Bequeathing (in will)" , "Departing" .)