Opposite of odd (4)
I believe the answer is:
even
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">opposite of odd</span>' is the definition.<br/ ><span class="explanation-format__explanation">('even' is the opposite to 'odd')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for even that I've seen before include "When darkness starts to fall" , "Crisp and ---, how King Wenceslas found the snow" , "exact" , "of consistent quality" , "Flat, regular" .)