Keen insight (12)
(Other definitions for perspicacity that I've seen before include "Clear-mindedness - crappy cities (anag)" , "Insight, perception" , "Astute intelligence" , "Insight into and understanding of things" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">keen insight</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for acumen that I've seen before include "Business sense" , "Sharpness, penetration, quickness of perception" , "Shrewdness, intelligence in business" , "brightness" , "ingenuity" .)