Plutoid chosen as the name for Pluto-like objects
The IAU is an official organization, made up of astronomers from around the world, which decides on all things astronomical, such as the names of stars and of newly discovered objects. This is one of the many tasks it has been performing since the early 1900's. The official line they came up with at a recent meeting in Oslo (Norway) is as follows:
Note that the moons of plutoids are not themselves plutoids, even though the may be massive enough to pull themselves into an almost spherical shape. In addition, the dwarf planet Ceres is not a plutoid as it is located in the asteroid belt between Mars and Jupiter - well inside the orbit of Neptune.