Plutino
/pluːˈtiːnəʊ
/noun
A small planet-like body orbiting the sun in the region of the Kuiper belt and in resonance with Neptune.Pluto and its ensemble of siblings called Plutinos cross Neptune's path around the Sun....
- It's a plutino -- an object that orbits the Sun in the same amount of time as Pluto, but is too small to be called a planet.
Origin
1990s: from the name of Pluto (because they have a similar orbit) + the Italian diminutive suffix -ino.