Noah Webster
Shrewd
SHREWD, adjective
1. Having the qualities of a shrew; vexatious; troublesome; mischievous. Obs.
2. Sly; cunning; arch; subtil; artful; astute; as a shrewd man.
3. Sagacious; of nice discernment; as a shrewd observer of men.
4. Proceeding from cunning or sagacity, or containing it; as a shrewd saying; a shrewd conjecture.
5. Painful; vexatious; troublesome.
Every of this number
That have endured shrewd nights and days with us. Obs. Shak.
No enemy is so despicable but he may do one a shrewd turn. Obs.
L'Estrange.