giant planet

American

[jahy-uhnt plan-it] / ˈdʒaɪ ənt ˈplæn ɪt /

noun

Astronomy.

any of the four largest planets in our solar system, which in order of size, from the largest, are Jupiter, Saturn, Uranus, and Neptune.

giant planet British

noun

any of the planets Jupiter, Saturn, Uranus, and Neptune, characterized by large mass, low density, and an extensive atmosphere

"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

Etymology

Origin of giant planet

First recorded in 1865–70

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.

Even more surprising, its metallicity is lower than that of its own host star, making it unlike any giant planet studied so far.

From Science Daily • Apr. 6, 2026

The system is only 17 million years old and has a giant planet, HIP 67522 b, orbiting close to its star.

From Space Scoop • Jul. 17, 2025

The dates suggested the impacts that shattered the parent objects happened startlingly early, most likely driven by a giant planet migration at 11 million years, just as the inner planets were finishing being formed.

From Science Magazine • Apr. 16, 2024

The contrast in color will also make the pair visually impressive, with the silvery lunar glow next to the distinct yellow tint of the giant planet.

From National Geographic • Dec. 6, 2023

Painted on one side was a giant planet.

From "The Missing Mitt (The Hardy Boys: Secret Files, #2)" by Franklin W. Dixon

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