Quickly run out after everyone, say (7)
I believe the answer is:
allegro
'quickly' is the definition.
(I've seen this in another clue)
'run out after everyone say' is the wordplay.
'run out' becomes 'RO' (cricket abbreviation).
'after' means one lot of letters go next to another.
'everyone' becomes 'all' (all people).
'say' becomes 'eg' (short for 'exempli gratia', 'for example' in Latin).
'all'+'eg'='alleg'
'ro' after 'alleg' is 'ALLEGRO'.
(Other definitions for allegro that I've seen before include "Lively, quick (mus.)" , "Musically fast and lively - legal or what?" , "musical term" , "Brisk musical piece" , "Brisk and lively tempo, musically" .)