A/one smart cookie noun phrase
Used to describe a person who is smart, clever or intelligent
John can solve every puzzle in the blink of an eye. He is one smart cookie in my class.
Through the way he talks, I can tell that he is a smart cookie.
To use one's own intelligence
A young person who is very clever and successful.
Wise or intelligent poeple think alike or have the same ideas
1. Lit. Very sharp.
2. Very smart.