adj.
  - having or showing sharp powers of judgement; astute.
- archaic (of weather) piercingly cold. ▸(of a blow) severe. ▸mischievous; malicious. 
Derivative
  
    - shrewdly adv.
- shrewdness n.
 
  Etymology
  ME (in the sense ‘evil in nature or character’): from shrew in the sense ‘evil person or thing’, or as the past part. of obs. shrew ‘to curse’.