Shrewd (adjective)

1. Clever at achieving one's goals by subtle or cunning means.
2. Having or showing sharp powers of judgement; astute.

Origin:

The word "shrewd" comes from old english "scrēawd" and means clever or sharp-witted.

Examples:

1. He was a shrewd businessman who always seemed to come out on top.
2. She had a shrewd mind and was able to solve problems quickly.
3. He was known for his shrewd negotiation tactics.
4. The politician showed a shrewd understanding of the issues.
5. She was a shrewd investor, always able to make smart decisions with her money.