Kept woman as cure, not remedy (9)
I believe the answer is:
courtesan
'kept woman' is the definition.
(courtesan is a kind of kept woman)
'as cure not remedy' is the wordplay.
'remedy' is an anagram indicator (I've seen this in other clues).
'as'+'cure'+'not'='ascurenot'
'ascurenot' is an anagram of 'COURTESAN'.
(Other definitions for courtesan that I've seen before include "paramour" , "Fanny Hill, perhaps" , "Kept woman" , "lover" , "odalisque" .)