jupiter definition planet
Jupiter. Jupiter is the fifth planet from the Sun and the largest planet in the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in the Solar System combined.Jupiter is classified as a gas giant along with Saturn, Uranus and Neptune.upiter (noun). one of the planets, being the brightest except Venus, and the largest of them all, its mean diameter being about 85,000 miles. It revolves about the sun in 4,332.6 days, at a mean distance of 5.2028 from the sun, the earth's mean distance being taken as unity. Origin: [L., fr. Jovis pater.