Word.ws English Dictionary

Planet Nine

Planet Nine proper noun: a theoretical ninth planet in the Solar system, the gravitational effects of which would explain the improbable orbital configuration of a group of trans-Neptunian objects that orbit mostly beyond the Kuiper belt.

planet nine: a theoretical ninth planet in the Solar system, the gravitational effects of which would explain...
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Proper noun

Planet Nine

  1. A theoretical ninth planet in the Solar system, the gravitational effects of which would explain the improbable orbital configuration of a group of trans-Neptunian objects that orbit mostly beyond the Kuiper belt.

Forms of Planet Nine

alternative formPlanet 9
alternative formPlanet IX

Questions about Planet Nine

What does Planet Nine mean?
Planet Nine means a theoretical ninth planet in the Solar system, the gravitational effects of which would explain the improbable orbital configuration of a group of trans-Neptunian objects that orbit mostly beyond the Kuiper belt.
What part of speech is Planet Nine?
Planet Nine is a proper noun.

Words near Planet Nine in the dictionary

  1. planet gear
  2. planet gears
  3. Planet Genesis
  4. Planet IX
  5. Planet Methuselah
  6. Planet Nine
  7. planet placement
  8. Planet Thanet
  9. planet wheel
  10. planet wheels
  11. Planet X

Source and license

Adapted from Wiktionary: Planet Nine (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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