Synonyms for Planet (same or very similar meaning)
WordNet sense 1 (a person who follows or serves another):
satellite
WordNet sense 2 ((astronomy) any of the nine large celestial bodies in the solar system that revolve around the sun and shine by reflected light; Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto in order of their proximity to the sun; viewed from the constellation Hercules, all the planets rotate around the sun in a counterclockwise direction):
major planet
From the ODE community, based on WordNet
add/edit