Elite revolutionary stirs soft drink (5,4)
I believe the answer is:
cream soda
'soft drink' is the definition.
(I know that cream soda is a type of soft drink)
'elite revolutionary stirs' is the wordplay.
'elite' becomes 'cream' (as in the cream of the crop).
'revolutionary' is a reversal indicator.
'stirs' becomes 'ados' ('ado' can be a synonym of 'stir').
'ados' written backwards gives 'soda'.
'cream'+'soda'='CREAM SODA'
(Other definitions for cream soda that I've seen before include "Carbonated soft drink" , "Vanilla-flavoured pop" , "Vanilla-flavoured fizzy drink" , "Sparkling stuff" .)