Weirder (6)
I believe the answer is:
eerier
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">weirder</span>' is the definition.<br/ ><span class="explanation-format__explanation">(eerie means odd or strange)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for eerier that I've seen before include "Weirder" , "More spooky" , "More mysterious" , "More strange and frightening" , "More strangely frightening" .)