Everyone, for example, has half roll on fast (7)
I believe the answer is:
allegro
'fast' is the definition.
('allegro' can be similar in meaning to 'fast')
'everyone for example has half roll' is the wordplay.
'everyone' becomes 'all' (I've seen this before).
'for example' becomes 'eg' ('e.g.' can be a synonym of 'for example').
'has' means one lot of letters go next to another.
'half' means to take half the letters.
'roll' halved is 'ro'.
'all'+'eg'+'ro'='ALLEGRO'
'on' is the link.
(Other definitions for allegro that I've seen before include "Quickly (in music)" , "rather quickly" , "Scored at a brisk speed" , "In rapid tempo" , "Musically fast and lively - legal or what?" .)