Constant sex appeal in actual performance (7)
I believe the answer is:
recital
'performance' is the definition.
(I know that recital is a type of performance)
'constant sex appeal in actual' is the wordplay.
'constant' becomes 'c' (mathematical abbreviation).
'sex appeal' becomes 'it'.
'in' is an insertion indicator.
'actual' becomes 'real' (similar in meaning).
'c'+'it'='cit'
'cit' placed within 'real' is 'RECITAL'.
(Other definitions for recital that I've seen before include "Performance, usually musical" , "Public musical performance" , "Article about musical entertainment" , "Chamber music concert" , "Musician's performance" .)