Pet hate (7)
I believe the answer is:
bugbear
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pet hate</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for bugbear that I've seen before include "Cause of excessive anxiety" , "Object of obsessive, foolish fear" , "constant worry" , "Nasty goblin - cause of fear" , "Cause of great distress" .)