Neptunian a. : Of or pertaining to the ocean or sea.

Neptunian a. : Formed by water or aqueous solution; as, Neptunian rocks.

Neptunian n. : Alt. of Neptunist

Example:
Spiritually speaking, has anyone done research on the Neptunian theory?

Taxonomy
Neptune, planet, Neptune in fiction, Triton, The planet Neptune, Neptunian, free encyclopedia, Neptunians, moons, Neptune Crossing, novel, the solar system, character, fiction, sea planet, Earth colonists, Neptune's largest moon, north pole.

Defination from the web:
Neptunian. ... and in "Bender's Big Score," where its North Pole is the location of Robot Santa's Death Fortress, with stunted Neptunian "elves" working for him. ... Ceres · Asteroids · Pluto • other trans-Neptunian objects • Comets • (fictional planets) Other systems ...