neptune

¹

[ nep-toon, -tyoon ]

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.

Neptune

²

[ nep-toon, -tyoon ]

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.

Neptune

¹

/ ˈnɛptjuːn /

noun

1. the Roman god of the sea Greek counterpartPoseidon

Neptune

²

/ 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

Neptune

/ 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

Neptune

¹

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.” )

Neptune

²

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

Notes

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.

Word History and Origins

Origin of neptune¹

< New Latin Neptunea; Neptune, -ea

Example Sentences

Lakes on Titan are full of methane, and the chemical is a major component of the giant planets Jupiter, Neptune, and so forth.

From The Daily Beast

For you, Saturn trining Neptune is a wake-up call to document ideas, first, and then punt them out into the universe.

From The Daily Beast

But the opposition of Mars and Neptune indicates that the symptom is the cause.

From The Daily Beast

Mercury squaring Neptune, later in the week, makes you hyper-realistic, if to a fault.

From The Daily Beast

A Mars-Neptune opposition assures that current naysayers will end up kissing your ring.

From The Daily Beast

Reckoning that Neptune is the outermost planet of the solar system, that system would have a diameter of 5,584 millions of miles.

From Project Gutenberg

The captain immediately went on deck, and Neptune hailed from the fore part of the rigging, "What ship?"

From Project Gutenberg

Strange to say, the dog Neptune was the only one on board that appeared to mourn the loss of this passenger.

From Project Gutenberg

Tell mother not to be uneasy on that point, for though Neptune has the heart of a lion he has the temper of a lamb.

From Project Gutenberg

Our main radio is dead without fuel to run its dynamotors, and our auxiliary set hasn't the power to reach Neptune.

From Project Gutenberg

Related Words

• earth