Abnormal fear (6)
I believe the answer is:
phobia
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">abnormal fear</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 phobia that I've seen before include "Irrational and lasting fear" , "An irrational fear or dislike" , "Irrational hatred" , "Aversion" , "A lasting abnormal fear of something" .)