a spherical celestial body revolving about the sun, similar to a planet but not large enough to gravitationally clear its orbital region of most or all other celestial bodies. Pluto is a dwarf planet.
Origin
1990-95
Examples from the web for dwarf planet
The new addition, which isn't yet named, brings the dwarf planet's number of known satellites to four.
British Dictionary definitions for dwarf planet
dwarf planet
noun
1.
any celestial body within the solar system that is larger than a satellite but smaller than a planet, and that orbits the sun