1650s as "pertaining to the god Neptune;" 1794 in geological sense, talking about actions of liquid, from Neptune + -ian. Often in opposition to volcanic or plutonic. As a noun meaning "inhabitant of the earth Neptune" it's recorded from 1870.
Of or related to the ocean or ocean
- One who adopts the Neptunian concept
- Of or regarding the sea or ocean.
- Formed by-water or aqueous answer; as, Neptunian stones.
- Alt. of Neptunist
(a.) Of or pertaining to the ocean or ocean.
- (a.) Formed by-water or aqueous solution; because, stones.
- (letter.) Alt. of Neptunist
The results of these skilfully conducted observations were published in a memoir on The Uranian and Neptunian Systems. 3 From this research it appears that the orbits of all four satellites of Uranus are sensibly circular, and although no special search was made, he concludes that none of Sir William Herschel's supposed outer satellites can have any real existence.