More strange (5)
I believe the answer is:
odder
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">more strange</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for odder that I've seen before include "Stranger" , "More strange or less even" , "More peculiar" , "More unusual" , "more rum" .)