Lasciviousness (9)
I believe the answer is:
prurience
'lasciviousness' is the definition.
(I know that lasciviousness can be written as prurience)
This is the entire clue.
(Other definitions for prurience that I've seen before include "Lust" , "Morbid interest in sex etc" , "Lewdness -- epic rerun (anag)" , "Salaciousness" , "Unhealthy interest in sex" .)