It's often used to describe the creation of simple objects, like toys or tools, but can also be used figuratively to describe a gradual reduction or diminishment of something.
Here are some examples:
* Literal: He whittled a wooden bird for his daughter.
* Figurative: The long hours of work whittled away at her free time.
Other meanings:
* Whittle down: To reduce something gradually, like a list or a budget.
* Whittle away at: To gradually diminish something, like a problem or an argument.