Definitions: (1) cunningly artful; (2) keen-witted in practical concerns; possessing useful smarts, insightful; (3) acute perception and sound judgment; savvy, sharp
Synonyms: Shrewd stresses pragmatic cleverness; astute combines shrewdness, perspicacity, and diplomatic skill; perspicacious implies unusual power to see through, and understand, what is puzzling or hidden; sagacious suggests wisdom, penetrating thought, and farsightedness.