1Having good intelligence or judgment; clever, smart, or wise — able to understand and act appropriately in a given situation.
彼は問題をすぐに理解する賢い学生だ。
He is a smart student who understands problems quickly.
こんなときこそ、賢い判断をすることが求められる。
It's precisely at times like this that a wise decision is called for.
あの犬はとても賢くて、新しい芸をすぐに覚えた。
That dog is very clever and learned new tricks quickly.
少しでも賢く節約する方法を探している。
I'm looking for smarter ways to save even a little money.
2Used especially of children or pets to mean well-behaved or obedient — a colloquial usage centered in the Kansai region.
うちの子は今日はずっと賢くしているよ。
My child has been well-behaved all day today.
この犬は賢くて、呼べばすぐに戻ってくる。
This dog is obedient and comes right back when called.