Mischievous tyke (3)
I believe the answer is:
imp
'mischievous tyke' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for imp that I've seen before include "Naughty demon" , "Mischievous monkey" , "Mischievous child" , "Small mischievous sprite" , "Young troublemaker" .)