gas giant

American

[gas jahy-uhnt] / ˈgæs ˌdʒaɪ ənt /

noun

Astronomy.

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.

gas giant British

noun

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

gas giant Scientific

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.
Also called Jovian planet
Compare terrestrial planet

Etymology

Origin of gas giant

First recorded in 1950–55

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Many of the lawsuits filed against oil and gas giants by state and local authorities are modeled on successful legal actions taken against the tobacco industry in the 1990s.

From Barron's

Small, rocky planets circle close to their star, while large gas giants orbit at greater distances.

From Science Daily

Beyond our neighborhood, astronomers have identified many gas giant exoplanets, some far larger than Jupiter.

From Science Daily

BP said it was halting stock buybacks as the oil and gas giant said it wanted to rebuild its balance sheet.

From MarketWatch

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023