Naughty sprite let go mischievous spirit (11)
I believe the answer is:
poltergeist
'mischievous spirit' is the definition.
(I've seen this in another clue)
'naughty sprite let go' is the wordplay.
'naughty' is an anagram indicator.
'sprite'+'let'+'go'='spriteletgo'
'spriteletgo' is an anagram of 'POLTERGEIST'.
(Other definitions for poltergeist that I've seen before include "Ghost that makes strange noises and disorders furniture" , "Noisy ghost" , "Active ghost" , "Mischievous spirit" , "Noisy spook" .)