plu·ti·no 
(pl-tēnō)
(pl-tēnō)n. pl. plu·ti·nos
A trans-Neptunian Kuiper belt object that orbits the Sun in the same time period as Pluto, making exactly two orbits for every three orbits of Neptune.
[PLUT(O) + -ino, diminutive suff. (as in NEUTRINO).]