Definition

1. Proper noun:
   • The eighth planet from the Sun: A giant planet in our solar system, characterized as an ice giant with a ring system composed of ice particles and dust. Its existence was mathematically predicted before being visually confirmed.
   • (Roman mythology) The god of the sea: The Roman deity who rules over all freshwater and the sea, identified as the counterpart to the Greek god Poseidon.

Usage Examples

• Proper noun (Astronomy):

  • Neptune is the windiest planet in our solar system.
  • Voyager 2 is the only spacecraft to have visited Neptune.
  • Neptune's blue color comes from methane in its atmosphere.

• Proper noun (Mythology):

  • In Roman myths, Neptune is often depicted with a trident.
  • The sailors prayed to Neptune for a safe voyage across the ocean.

Advanced Usage

• "to be a Neptune of something": (Figurative, rare) To be a dominant ruler or master of a particular domain, analogous to the god's rule over the sea.
  • In the world of classical music, he was a Neptune of the piano.
• Capitalization: The word is always capitalized, whether referring to the planet or the god.

Variants and Related Words

• Neptunian (adj): Pertaining to the planet Neptune or the god Neptune.
  • Neptunian winds can reach supersonic speeds.
  • The temple had Neptunian symbols carved into its walls.
• Poseidon (n): The Greek equivalent of the Roman god Neptune.

Synonyms

• (For the planet): The Blue Planet, ice giant. (Note: "The Blue Planet" is more commonly used for Earth, but is sometimes a poetic reference for Neptune).
• (For the god): God of the sea, ruler of the deep.

Related Phrases and Idioms

• "To worship Neptune": (Historical/Figurative) To be a sailor or to spend one's life at sea.
  • For forty years, he worshipped Neptune, sailing every ocean.
• "Neptune's domain": A poetic term for the sea or ocean.
  • The ship vanished into Neptune's domain during the storm.

Noun

1. a giant planet with a ring of ice particles; the 8th planet from the sun is the most remote of the gas giants
   • the existence of Neptune was predicted from perturbations in the orbit of Uranus and it was then identified in 1846
2. (Roman mythology) god of the sea; counterpart of Greek Poseidon