adjective
clever, intelligent
Synonyms: acute, argute, artful, astucious, astute, brainy, cagey, calculating, canny, crafty, cunning, cutting, deep, discerning, discriminating, farsighted, foxy, heady, ingenious, inside, in the know, judicious, keen, knowing, on the inside, on top of, penetrating, perceptive, perspicacious, piercing, probing, profound, prudent, quick-witted, sagacious, savvy, sensible, shark, sharp, slick, slippery, sly, smart, smooth, streetwise, tricky, underhand, up on, wily, wise, wised up
Antonyms: foolish, frivolous, naive, stupid, unthinking