Fast or rising support for everyone, say (7)
I believe the answer is:
allegro
'fast' is the definition.
('allegro' can be similar in meaning to 'fast')
'or rising support for everyone say' is the wordplay.
'rising' is a reversal indicator (going up in a down clue).
'support for' is a charade indicator (letters next to each other).
'everyone' becomes 'all' (I've seen this before).
'say' becomes 'eg'.
'or' backwards is 'ro'.
'all'+'eg'='alleg'
'ro' after 'alleg' is 'ALLEGRO'.
(Other definitions for allegro that I've seen before include "In a brisk and lively manner" , "Moving fast" , "Scored at a brisk speed" , "(In music) briskly" , "Gaily, lively (music)" .)