(Roman mythology) god of the sea; counterpart of Greek Poseidon
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"
(Astron.) The remotest major planet of our solar system, discovered -- as a result of the computations of Leverrier, of Paris -- by Galle, of Berlin, September 23, 1846. It is classed as a gas giant, and has a radius of 22,716 km and an estimated mass of 1.027 x 1026 kg, with an average density of 2.27 g/cc. Its mean distance from the sun is about 5,000,000,000 km (3,106,856,000 miles), and its period of revolution is about 164.78 years.
Origin: [L. Neptunus.]
The god of the ocean and of earthquakes.
The eighth planet in our solar system, represented in astronomy and astrology by u2646.
Origin: From Neptunus.
the son of Saturn and Ops, the god of the waters, especially of the sea. He is represented as bearing a trident for a scepter
the remotest known planet of our system, discovered -- as a result of the computations of Leverrier, of Paris -- by Galle, of Berlin, September 23, 1846. Its mean distance from the sun is about 2,775,000,000 miles, and its period of revolution is about 164,78 years
Origin: [L. Neptunus.]
Neptune is the eighth and farthest planet from the Sun in the Solar System. It is the fourth-largest planet by diameter and the third-largest by mass. Among the gaseous planets in the solar system, Neptune is the most dense. Neptune is 17 times the mass of Earth and is slightly more massive than its near-twin Uranus, which is 15 times the mass of Earth but not as dense. On average, Neptune orbits the Sun at a distance of 30.1 AU, approximately 30 times the Earth–Sun distance. Named for the Roman god of the sea, its astronomical symbol is ♆, a stylised version of the god Neptune's trident. Neptune was the first planet found by mathematical prediction rather than by empirical observation. Unexpected changes in the orbit of Uranus led Alexis Bouvard to deduce that its orbit was subject to gravitational perturbation by an unknown planet. Neptune was subsequently observed on 23 September 1846 by Johann Galle within a degree of the position predicted by Urbain Le Verrier, and its largest moon, Triton, was discovered shortly thereafter, though none of the planet's remaining 12 moons were located telescopically until the 20th century. Neptune has been visited by only one spacecraft, Voyager 2, which flew by the planet on 25 August 1989.
Chambers 20th Century Dictionary
nep′tūn, n. (Rom. myth.) the god of the sea, identified with the Greek Poseidon, represented with a trident in his hand: (astron.) the outermost planet of the solar system, discovered in 1846.—adj. Neptū′nian, pertaining to the sea: (geol.) formed by water: applied to stratified rocks or to those due mainly to the agency of water, as opposed to Plutonic or Igneous.—n. Nep′tūnist, one who holds the Neptunian theory in geology—also adj. [L. Neptunus.]
The Nuttall Encyclopedia
the chief marine deity of the Romans, and identified with the Poseidon of the Greeks, is represented with a trident in his hand as his sceptre.
the remotest planet of the solar system at present known; it is twice as far distant from the sun as Uranus (q. v.) is, deemed before its discovery the remotest; its diameter is four times greater than that of the earth, and it takes 60,126 days to revolve round the sun, accompanied by a solitary satellite; it was discovered in 1846 by Adams (q. v.) and Leverrier (q. v.), who were guided to the spot where they found it from the effect of its neighbourhood on the movements of Uranus.
U.S. National Library of Medicine
The eighth planet in order from the sun. It is one of the five outer planets of the solar system. Its two natural satellites are Nereid and Triton.
One of the planets in the Solar System.
From its discovery in 1846 until the subsequent discovery of Pluto in 1930, Neptune was the farthest known planet. Upon Pluto's discovery Neptune became the penultimate planet, save for a 20-year period between 1979 and 1999 when Pluto's elliptical orbit brought it closer to the Sun than Neptune.
The numerical value of Neptune in Chaldean Numerology is: 2
The numerical value of Neptune in Pythagorean Numerology is: 5
Sample Sentences & Example Usage
Bacchus hath drowned more men than Neptune.
While we do not believe Neptune is leaving the Macau scene we do believe that more junket closures are likely and that liquidity could increasingly become a concern that could drive further downside to the VIP story.
Gliese 1214 b is a type of planet we call a Super-Earth -- a bit bigger than Earth, a bit smaller than Neptune. It's not dense enough to be rocky so it's probably like a warm mini-Neptune. There's nothing like it in our solar system and we don't really know what to expect, on my wish list for the future is a telescope to study exoplanets like Gliese 1214 b in more detail. I want to know what's going on beneath that cloud layer !
Images & Illustrations of Neptune
Translations for Neptune
From our Multilingual Translation Dictionary
Get even more translations for Neptune »
Find a translation for the Neptune definition in other languages:
Select another language: