Tidier (6)
I believe the answer is:
neater
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tidier</span>' is the definition.<br/ ><span class="explanation-format__explanation">('neat' can be a synonym of 'tidy')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for neater that I've seen before include "Less messy" , "More tidy and uncluttered" , "straighter" , "Tidier" , "Better" .)