More acute (7)
I believe the answer is:
sharper
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">more acute</span>' is the definition.<br/ ><span class="explanation-format__explanation">('sharp' can be similar in meaning to 'acute')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for sharper that I've seen before include "More keen or bitter" , "More acerbic" , "More acute" , "showing greater astuteness" , "Cheat" .)