The word "Plutoid" means "Pluto-like", referring to Pluto, what used to be considered the ninth planet of our solar system, but which has since been downgraded. Plutoids are the term for the new category of dwarf planets. Plutoids are defined as dwarf planets that orbit the sun at a distance further than Neptune. They have enough mass for their own gravitational strength to give them a regular round shape. Dwarf planet, Eris, although 27 percent larger than Pluto, is also classed as a plutoid.