Badly behaved child (4)
I believe the answer is:
brat
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">badly behaved child</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for brat that I've seen before include "child - that's a nuisance" , "Annoying child" , "An obnoxious or spoiled child" , "Marie ---, birth-control pioneer" , "Nasty little kid" .)