Deriving pleasure from inflicting pain (8)

I believe the answer is:
sadistic
'deriving pleasure from inflicting pain' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for sadistic that I've seen before include "nasty" , "Gaining pleasure from inflicting pain" , "Enjoying inflicting pain" , "This kind of person enjoys cruelty" , "Enjoying others' pain" .)