Perspicacity (6)
I believe the answer is:
acumen
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">perspicacity</span>' is the definition.<br/ ><span class="explanation-format__explanation">(acumen is a kind of perspicacity)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for acumen that I've seen before include "Keen perception" , "brightness" , "Forming judgement" , "Mental sharpness as in business" , "Discernment - insight" .)