Exhibitionist performance cancelled (4,3)
I believe the answer is:
show off
'exhibitionist' is the definition.
(I know that exhibitionist can be written as show-off)
'performance cancelled' is the wordplay.
'performance' becomes 'show' (eg a theatrical show).
'cancelled' becomes 'off' (similar in meaning).
'show'+'off'='SHOW-OFF'
(Other definitions for show off that I've seen before include "message that will disappoint the paying fans?" , "An ostentatious braggart" , "Self-publicist" , "Flaunt - exhibitionist" , "news when all the actors are ill?" .)