Past lovers, naked (4)
I believe the answer is:
over
'past' is the definition.
(both can mean finished)
'lovers naked' is the wordplay.
'naked' indicates a hidden word (with the letters around the hidden word taken off).
'OVER' is hidden within 'lovers'.
(Other definitions for over that I've seen before include "Accomplished" , "Higher than; finished" , "See 18" , "Finished - across - in excess" , "balls > left" .)