Shrewd1. (a.) Astute; sharp; wily; cunning; as, a shrewd politician.
2. (a.) Inclining to shrew; disposing to curse or scold; hence, vicious; malicious; evil; wicked; mischievous; vexatious; rough; unfair; shrewish.
3. (superl.) Able or clever in practical affairs; sharp in business; astute; sharp-witted; sagacious; keen; as, a shrewd observer; a shrewd design; a shrewd reply.
Thesaurus Entries
Byzantine, Daedalian, Machiavellian, Machiavellic, acute, all-knowing, apperceptive, appercipient, apprehending, apprehensive, arch, artful, astute, aware, cagey, calculated, calculating, canny, clever, cognizant, comprehending, conscious, crafty, cunning, cute, deceitful, deep, deep-laid, designing, devious, diplomatic, discerning, farsighted, feline, foresighted, foxy, guileful, heady, ingenious, insidious, insightful, intelligent, inventive, judicious, keen, knowing, knowledgeable, manipulative, mindful, omniscient, pawky, penetrating, perceptive, percipient, perspicacious, piercing, polite, politic, prehensile, probing, prudent, quick-witted, ready, resourceful, sagacious, sage, savvy, scheming, sensible, serpentine, sharp, shifty, slick, slippery, sly, smart, smooth, snaky, sneaky, sophistical, stealthy, strategic, subtile, subtle, supple, tactical, tidy, trickish, tricksy, tricky, understanding, vulpine, wary, wily, wise