shrewd /ˈʃrud, ||ˈsrud/
  (a.)精明的,銳利的,劇烈的,機靈的,厲害的
  Shrewd a. [Compar. Shrewder superl. Shrewdest.]
  1. Inclining to shrew; disposing to curse or scold; hence, vicious; malicious; evil; wicked; mischievous; vexatious; rough; unfair; shrewish. [Obs.]
     [Egypt] hath many shrewd havens, because of the great rocks that ben strong and dangerous to pass by.   --Sir J. Mandeville.
  Every of this happy number
  That have endured shrewd days and nights with us.   --Shak.
  2. Artful; wily; cunning; arch.
     These women are shrewd tempters with their tongues.   --Shak.
  3. Able or clever in practical affairs; sharp in business; astute; sharp-witted; sagacious; keen; as, a shrewd observer; a shrewd design; a shrewd reply.
     Professing to despise the ill opinion of mankind creates a shrewd suspicion that we have deserved it.   --Secker.
  Syn: -- Keen; critical; subtle; artful; astute; sagacious; discerning; acute; penetrating.
  Usage: Shrewd, Sagacious. One who is shrewd is keen to detect errors, to penetrate disguises, to foresee and guard against the selfishness of others. Shrewd is a word of less dignity than sagacious, which implies a comprehensive as well as penetrating mind, whereas shrewd does not.
  -- Shrewd*ly, adv. -- Shrewd*ness, n.
  ◄ ►
  shrewd
       adj 1: marked by practical hardheaded intelligence; "a smart
              businessman"; "an astute tenant always reads the small
              print in a lease"; "he was too shrewd to go along with
              them on a road that could lead only to their
              overthrow" [syn: astute, sharp]
       2: used of persons; "the most calculating and selfish men in
          the community" [syn: calculating, calculative, conniving,
           scheming]