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.’
1990s from the name of Pluto (because they have a similar orbit) + the Italian diminutive suffix -ino.
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