Unusual; peculiar (8)
I believe the answer is:
abnormal
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">unusual</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >'<span class="explanation-format__original">peculiar</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for abnormal that I've seen before include "Deviating from the usual" , "Highly unusual" , "Freakish" , "Not typical or usual" , "Anomalous" .)