Unconventional; crazy (5)
I believe the answer is:
wacky
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">unconventional</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >'<span class="explanation-format__original">crazy</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for wacky that I've seen before include "Bonkers" , "Oddly crazy" , "Eccentric - erratic" , "Oddly amusing (colloq.)" , "Funny in a peculiar way" .)