Warped tail of sick raven (5)
I believe the answer is:
kinky
'warped' is the definition.
(thesaurus)
'tail of sick raven' is the wordplay.
'tail of' says to take the final letters.
'raven' becomes 'inky' (both can mean black).
The last letter of 'sick' is 'k'.
'k'+'inky'='KINKY'
(Other definitions for kinky that I've seen before include "Twisted" , "Irritatingly self-satisfied" , "depraved" , "Given to deviant sexual practices" , "Sexually unusual" .)