Mischief-maker shouted 'fruit tree' (6)
I believe the answer is:
medlar
'fruit tree' is the definition.
(I know that medlar is a type of fruit tree)
'mischief-maker shouted' is the wordplay.
'mischief-maker' becomes 'meddler' (someone meddling in things).
'shouted' shows a homophone (sound like) (how the word might sound if shouted).
'meddler' sounds like 'MEDLAR'.
(Other definitions for medlar that I've seen before include "Apple-like fruit" , "Led ram (anag) - fruit related to the apple" , "Red Mal turns to the fruit tree" , "Dermal (anag.)" .)