neptune

¹ American  

[nep-toon, -tyoon] / ˈnɛp tun, -tyun /

noun

1. any whelk of the genus Neptunea, especially N. decemcostata, common along the eastern coast of North America and having a shell with seven to ten raised reddish-brown spiral ridges on a pale beige or yellow background.

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Neptune ² American  

[nep-toon, -tyoon] / ˈnɛp tun, -tyun /

noun

1. the ancient Roman god of the sea, identified with the Greek god Poseidon.

2. the sea or ocean.

   Neptune's mighty roar.

3. Astronomy. the planet eighth in order from the sun, having an equatorial diameter of 30,200 miles (48,600 km), a mean distance from the sun of 2794.4 million miles (4497.1 million km), a period of revolution of 164.81 years, and two moons.

4. a township in E New Jersey.

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Neptune ¹ British  

/ ˈnɛptjuːn /

noun

1. Greek counterpart: Poseidon.  the Roman god of the sea

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Neptune ² British  

/ ˈnɛptjuːn /

noun

1. the eighth planet from the sun, having fourteen known satellites, the largest being Triton and Nereid, and a faint planar system of rings or ring fragments. Mean distance from sun: 4497 million km; period of revolution around sun: 164.8 years; period of rotation: 14 to 16 hours; diameter and mass: 4.0 and 17.2 times that of earth respectively

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Neptune Scientific  

/ nĕp′to̅o̅n′ /

1. The eighth planet from the Sun and the fourth largest, with a diameter almost four times that of Earth. Neptune is a gas giant with a very active weather system, exhibiting extremely long and powerful storms with the fastest winds observed in the solar system. Neptune's axis is tilted 28.8° from the plane of its orbit, and its summer and winter seasons each last 40 years. For a period of 20 years out of every 248, Pluto's highly elliptical orbit crosses within that of Neptune. Neptune has four faint rings and 13 known moons and appears blue due to the absorption of red light by the methane within its atmosphere.

2. See Table at solar system

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Neptune ¹ Cultural  

1. The Roman and Greek god who ruled the sea.

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Neptune ² Cultural  

1. In astronomy, a major planet, the eighth planet from the sun. Neptune is named for the Roman god of the sea. Neptune is similar in size and composition to Uranus. It is usually visible only through a telescope and was discovered in the 1840s. For a period ending in 1999, Pluto's orbit took it inside the orbit of neptune. (See solar system; see under “Mythology and Folklore.”)

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Discover More

The eighth planet from the sun (the Earth is third) is named Neptune.

Neptune is frequently portrayed as a bearded giant with a fish's scaly tail, holding a large three-pronged spear, or trident.

Some astronomers have suggested that Pluto is not a planet in the usual sense but is an object more like an asteroid, and that Neptune, therefore, is actually the outermost planet.

Etymology

Origin of neptune

< New Latin Neptunea; Neptune, -ea

Example Sentences

Astronomers were surprised to learn in recent years that most Sun-like stars host at least one planet that falls between Earth and Neptune in size and orbits closer than Mercury does in our own solar system -- sizes and orbits absent from our solar system.

From Science Daily

Four large planets circle this energetic star, each ranging in size from Neptune to Jupiter.

From Science Daily

OceanXplorer's Neptune submersible is designed for scientific collection and observation, while its Nadir vessel has high-end cameras and lights for media content.

From Barron's

But as Julian Sancton tells us in his splendid “Neptune’s Fortune: The Billion-Dollar Shipwreck and the Ghosts of the Spanish Empire,” it is estimated that there was “as much as eight tons’ worth of gold on board, more than had ever sailed in a single Spanish ship,” and “more than a million silver coins,” in addition to precious-metal contraband and—another estimate—600 or so people.

From The Wall Street Journal

Especially moving in “Neptune’s Fortune” is the insight and empathy Mr. Sancton brings to his consideration of the book’s bedeviled but oddly gallant protagonist.

From The Wall Street Journal

Related Words

• earth