Here are some nouns that could be used to describe something or someone that is clever:
* Intelligence: A general mental capability, often characterized by reasoning, problem-solving, and learning.
* Wit: The ability to use words and ideas in a quick and clever way, often to be funny or amusing.
* Ingenuity: The ability to think of new and clever ideas and solutions.
* Cunning: Skill in deceiving others, especially in a clever and skillful way.
* Astuteness: The ability to understand things quickly and easily.
You could also use a noun phrase like:
* Cleverness
* A clever idea
* A clever trick
* A clever solution