Sprites arise if disturbed (7)
I believe the answer is:
fairies
'sprites' is the definition.
('fairy' can be a synonym of 'sprite')
'arise if disturbed' is the wordplay.
'disturbed' is an anagram indicator (the order of letters is disturbed).
'arise'+'if'='ariseif'
'ariseif' with letters rearranged gives 'FAIRIES'.
(Other definitions for fairies that I've seen before include "Creatures of our imagination" , "The little people" , "Mythical creatures at the bottom of the garden?" , "good people" , "Sprites" .)