From the Latin satelles
, meaning attendant
A attendant celestial body that revolves or is intended to revolve around a larger celestial body. For example, a planet orbits a sun and a moon orbits a planet. The Earth's moon orbits the Earth. Actually, that's not quite true. The moon and the Earth orbit each other as they both revolve around their common center of gravity. As the Earth is the larger of the two and, therefore, exerts more gravitational force, the moon does most of the revolving. 2.
A manmade object that orbits the Earth or some other celestial body. Satellites in Geosynchronous Earth Orbit (GEO) are placed in orbital slots such that they maintain their positions relative to the Earth's surface. Medium Earth Orbiting (MEO) and Low Earth Orbiting (LEO) satellites do not. See also GEO
, and MEO