Annoying kid (4)
I believe the answer is:
brat
'annoying kid' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for brat that I've seen before include "Brash young type" , "An obnoxious or spoiled child" , "Young rascal" , "Horrible child" , "Ill-mannered child" .)