A female just before the start of secret liaisons (7)
I believe the answer is:
affairs
'liaisons' is the definition.
('affair' can be a synonym of 'liaison')
'a female just before the start of secret' is the wordplay.
'female' becomes 'f' (abbreviation).
'just' becomes 'fair' ('fair' is associated in meaning with 'just'**).
'before' is a charade indicator (letters next to each other).
'the start of' indicates taking the first letters.
The first letter of 'secret' is 's'.
'a'+'f'+'fair'+'s'='AFFAIRS'
(Other definitions for affairs that I've seen before include "Business and financial dealings" , "Current ones are of interest to the public" , "Business; amours" .)