An expression used by astrologers to mean an object that physically exists in space. Examples would include planets, stars, moons, asteroids, comets, etc. The ecliptic, an imagined circle of the sun's apparent path through the sky, is not a celestial body.
Readers, please enjoy this guest blog post by Sandra Kynes, author of several books, including The Herb Gardener's Essential Guide, Plant Magic, and the new Witches' Encyclopedia of Magical Plants, among many others.
Although a few old books...