矮わい惑わく星せい

noun

dwarf planet

Astronomical term for a celestial body that orbits the sun and has sufficient mass for a nearly round shape, but has not cleared its neighboring region. Compare with 準惑星 (じゅんわくせい), which is the more common term in modern Japanese.

See also: 準惑星

• 冥めい王おう星せいは矮わい惑わく星せいに分ぶん類るいされている。

  Pluto is classified as a dwarf planet.