Meaning: This sentence describes the way leaves move in the cold, dry air of autumn, which makes them look like they are dancing.
Choice of Words: "Dance" is a verb that means to move in a lively and graceful way, often to music. "Leaves" are the flat green parts of a tree or plant. "Crisp" means firm and brittle, often used to describe the texture of food or air. "Air" is the mixture of gases that surrounds the Earth.