What is equatorial radius mean?

The equatorial radius is the distance from the center of a celestial body, such as a planet or moon, to its equator. It represents the body's radius at its widest point and is typically larger than the polar radius due to the body's rotation, which causes it to bulge at the equator. This measurement is crucial in understanding the body's shape, size, and gravitational field. For example, Earth's equatorial radius is about 6,378 kilometers.