Spoiled child (4)
I believe the answer is:
brat
'spoiled child' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for brat that I've seen before include "Unpleasant youngster" , "Ill-behaved child" , "Ill-mannered child" , "A spoiled badly-behaved child" , "Little terror" .)