giant planet

American  

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

noun

Astronomy.

1. 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

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

---

Etymology

Origin of giant planet

First recorded in 1865–70

Example Sentences

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

A giant planet wrapped by a scorching atmosphere as fluffy as cotton, WASP-107 b orbits a star about 200 light-years away.

From Science Daily • May 20, 2024

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

Every evening before Voyager l’s encounter with Jupiter, I could see that giant planet twinkling in the sky, a sight our ancestors have enjoyed and wondered at for a million years.

From "Cosmos" by Carl Sagan