Jupiter

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Roman Mythology The supreme god, patron of the Roman state and brother and husband of Juno. He came to be identified with the Greek Zeus. Also called Jove.
2. n. Astronomy The fifth planet from the sun, the largest and most massive in the solar system, having a sidereal period of revolution about the sun of 11.86 years at a mean distance of 778 million kilometers (483 million miles), a mean diameter of approximately 142,000 kilometers (88,000 miles), and a mass approximately 318 times that of Earth.

Century Dictionary and Cyclopedia

1. n. In Roman mythology, the supreme deity, the parallel of the Greek Zeus, and the embodiment of the might and national dignity of the Romans. The central seat of his cult was the Capitoline Hill at Rome, where he had the title of Optimus Maximus (Best Greatest). He was primarily a divinity of the sky, and hence was considered to be the originator of all atmospheric changes. His weapon was the thunderbolt. He controlled and directed the future, and sacrifices were offered to secure his favor at the beginning of every undertaking. He was also the guardian of property, whether of the state or of individuals. White, the color of the light of day, was sacred to him; hence, white animals were offered to him in sacrifice, his priests wore white caps, his chariot was drawn by four white horses, and the consuls were dressed in white when they sacrificed to him upon assuming office. The eagle was especially consecrated to him. The surviving artistic representations of Jupiter are comparatively late, and betray Greek influence, imitating the type of the Greek Zeus. Also called Jove.
2. n. The brightest of the superior planets, and the largest body of the solar system except the sun itself. Its sidereal period of revolution is 11.86198 Julian years, and its synodical period 399 days. Its mean distance from the sun is about 483,000,000 miles. Its equatorial diameter at its meandistance subtends an angle of 38″, so that its real diameter is about one tenth of that of the sun (which subtends 1,922″), and about 11 times that of the earth (the solar parallax being 8″.9). Jupiter is flattened at the poles by no less than one seventeenth of its diameter. Its mass is about ¼ of that at the sun, or 304 times that of the earth, making its mean density only 1.3, that of the earth being taken at 5.5. Gravity at its surface is 2½ times that at the earth. The most remarkable feature of the appearance of this planet is the equatorial fasciæ or bands which cross its disk. These fasciæ subsist generally for months or even years, but sometimes form in a few hours. They sometimes have a breadth of one sixth of the apparent disk of the planet. There are also spots of much greater permanence. It is, however, probable that no solid matter can be seen, and quite doubtful whether any exists, in the planet. The spots revolve about the axis in 9 hours, 55 minutes, and 35 seconds, out the white clouds in 5½ minutes less time. From his photometric observations, Zöllner calculates the albedo of Jupiter to be 0.6, so high a value as to suggest that the planet must be self-luminous. Jupiter has five satellites or moons. Their periods of revolution are as follows: I. 1d. 18h. 28m. 35.945s.; II. 3d. 13h. 17m. 53.735s.; III. 7d. 3h. 59m. 35.854s.; IV. 16d.. 18h. 5m. 6.928s.; V. 11h. 57½ m.
3. n. In alchemy, tin, which was supposed to be under the control of the planet Jupiter.
4. n. In heraldry, the tincture azure or blue in blazoning by the planets. See blazon, n.
5. n. In zoology, a finback whale. Also called Jupiter-fish.

Wiktionary

1. n. astronomy The fifth and by far the largest planet in the Solar System, a gas giant, represented by the symbol ♃ in astronomy. Jupiter is known for its Great Red Spot and many moons including the Galilean moons.
2. n. Roman mythology The King of the Gods, also called Jove. Equivalent to the Greek Zeus, Jupiter was one of the children of Saturn.

GNU Webster's 1913

1. n. (Rom. Myth.) The supreme deity, king of gods and men, and reputed to be the son of Saturn and Rhea; Jove. He corresponds to the Greek Zeus.
2. n. (Astron.) One of the planets, being the fifth from the sun, the brightest except Venus, and the largest of them all, its mean radius being about 43,345 miles (69,758 kilometers), almost exactly one-tenth that of the sun. It revolves about the sun in 4,332.6 days, at a mean distance of 5.2025 from the sun (778,140,000 km), the earth's mean distance (the astronomical unit) being taken as unity. It has a mass of 1.901 x 1027 kg, about one-thousandth that of the sun, and more than the remainder of the planets combined. It has an average solar day equal to 9.842 earth hours. The rapid revolution causes a noticeable flattening at the poles; the diameter at the equator is 71,370 km, and at the poles 66,644 km.

WordNet 3.0

1. n. (Roman mythology) supreme god of Romans; counterpart of Greek Zeus
2. n. the largest planet and the 5th from the sun; has many satellites and is one of the brightest objects in the night sky