keen judgment (6)
I believe the answer is:
acumen
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">keen judgment</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for acumen that I've seen before include "perspicacity" , "Good judgment" , "Ability to judge and decide quickly" , "Gumption" , "Being sharp" .)