Shrewd; sagacious (6)
I believe the answer is:
astute
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">shrewd</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that shrewd can be written as astute)</span><br/ ><br/ >'<span class="explanation-format__original">sagacious</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ ></span>
(Other definitions for astute that I've seen before include "Shrewd, wily" , "Wise" , "Statue (anag)" , "Discerning" , "Shrewd and sagacious" .)