gas giant

American  

[gas jahy-uhnt] / ˈgæs ˌdʒaɪ ənt /

noun

Astronomy.

1. a giant planet composed mostly of hydrogen and helium: the two gas giants in our solar system, Jupiter and Saturn, are sometimes called failed stars because their composition is similar to that of stars, but this is largely considered misleading, as gas giants, unlike brown dwarfs, do not form as stars do.

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gas giant British  

noun

1. one of the four planets in our solar system that are composed chiefly of hydrogen and helium, namely Jupiter, Saturn, Uranus, and Neptune

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gas giant Scientific  

1. A large, massive, low-density planet composed primarily of hydrogen, helium, methane, and ammonia in either gaseous or liquid state. Gas giants have swirling atmospheres primarily of hydrogen and helium, with no well-defined planetary surface; they are assumed to have rocky cores. They are also characterized by ring systems, although only Saturn's is readily visible from Earth. Our solar system contains four gas giants: Jupiter, Saturn, Uranus, and Neptune. The majority of extrasolar planets discovered so far are the size of the solar system's gas giants, although they orbit their stars much more closely and may differ in composition from ours.

2. Also called Jovian planet

3. Compare terrestrial planet

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Etymology

Origin of gas giant

First recorded in 1950–55

Example Sentences

See Examples For:

gas giant

He courted controversy shortly after taking over the association by changing its name, its logo and starting a partnership with Gazprom that turned the state-owned gas giant into the body’s biggest sponsor.

From The Wall Street Journal ● Sep. 14, 2026

Earth rotates much more slowly than a gas giant such as Saturn.

From Science Daily ● Aug. 10, 2026

French oil and gas giant TotalEnergies said Thursday net profit doubled in the second quarter as conflict in the Middle East pushed up hydrocarbon prices.

From Barron's ● Jul. 23, 2026

She became the first female member on the Nigerian board of oil and gas giant Shell in 2006, and four years later was appointed oil minister, the country's second most senior politician.

From BBC ● Jun. 17, 2026

I’m like that theoretical brown dwarf star or gas giant planet lurking at the far edges of our solar system, way beyond Pluto.

From "Shine!" by J.J. and Chris Grabenstein