Not as much (4)
I believe the answer is:
less
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">not as much</span>' is the definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for less that I've seen before include "In smaller quantity" , "A smaller amount" , "Fewer in number" , "Comparative of 'a little'" , "Fewer; minus" .)