Disruptive spirit (11)
I believe the answer is:
poltergeist
'disruptive spirit' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for poltergeist that I've seen before include "Mischievous ghost" , "Destructive spirit" , "Troublesome ghost" , "Noisy spook" , "Disturbing ghost" .)