gas giant

noun

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

Word Origin for gas giant

C20: coined by James Blish (1921–75), US science fiction writer

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

Examples from the Web for gas giant

Historical Examples of gas giant

There was a gas-giant planet, a mere fifteen million miles away.
Talents, Incorporated
William Fitzgerald Jenkins
The gas-giant planet far behind, and the only inner one on this side of the sun, would return their pulses only after minutes.
The Aliens
Murray Leinster
The gas-giant planet outward from the sun was a perceptible disk instead of a diffuse glow.
The Aliens
Murray Leinster
It made for a rendezvous over a pole of the gas-giant planet which was the fourth planet from Kandar's sun.
Talents, Incorporated
William Fitzgerald Jenkins
Then the shining cloud-bank of the gas-giant planet went black.
Talents, Incorporated
William Fitzgerald Jenkins

gas giant in Science

gas giant

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.