More rational
I believe the answer is:
saner
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">more rational</span>' is the definition.<br/ ><span class="explanation-format__explanation">('sane' can be similar in meaning to 'rational')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for saner that I've seen before include "Less mad" , "less as hatter?" .)