柯林斯詞典gas giant 1. N one of the four planets in our solar system that are composed chiefly of hydrogen and helium, namely Jupiter, Saturn, Uranus, and Neptune 氣態(tài)巨行星; 太陽系中主要由氫和氦組成的4大行星，即木星、土星、天王星和海王星 返回 gas giant