shrewd

adj.

[1]	clever , astute , sharp , smart , astute , cunning , canny , acute , sharp , keen-minded , keen , quick-witted , crafty , artful , manipulative , calculating , calculated , foxy , sly , wily , perceptive , percipient , perspicacious , discerning , wise , sage , sagacious , long-headed , intelligent , ingenious , Daedalian , inventive , resourceful
[2]	calculating , calculative , conniving , scheming