Evil girl without a date (4,3)
I believe the answer is:
sine die
'without a date' is the definition.
(Latin term meaning without a set date)
'evil girl' is the wordplay.
'evil' becomes 'sin' (I've seen this before).
'girl' becomes 'edie' ().
'sin'+'edie'='SINE DIE'
(Other definitions for sine die that I've seen before include "no time to make fresh start" , "undated" , "with no date for a restart" , "Indefinitely (Latin, as applied to sporting suspensions)" , "without a date" .)