zodiac

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Astronomy A band of the celestial sphere extending about 8° to either side of the ecliptic that represents the path of the principal planets, the moon, and the sun.
2. n. In astrology, this band divided into 12 equal parts called signs, each 30° wide, bearing the name of a constellation for which it was originally named but with which it no longer coincides owing to the precession of the equinoxes.
3. n. A diagram or figure representing the zodiac.
4. n. A complete circuit; a circle.

Century Dictionary and Cyclopedia

1. n. Of the moon or of a planet, the belt of the heavens within which the moon or a planet moves.
2. n. A belt of twelve constellations, extending about 8° on each side of the ecliptic. The constellations are , Aries; , Taurus; , Gemini; , Cancer; , Leo; , Virgo; , Libra; , Scorpio; , Sagittarius; , Capricornus; , Aquarius; , Pisces. The zodiac is also divided into twelve equal parts called signs, named after these constellations, and the first point of the sign Aries begins at the vernal equinox. The above symbols refer to the signs. The signs have been carried back by the precession of the equinoxes until they are now 25° behind the corresponding constellations on the average. But the position of the vernal equinox was originally, no doubt, between Aries and Taurus. There is strong evidence that the zodiac was formed at Babylon about 2100 b. c. There is a poetical description of the heavens written by Aratus in Macedonia in latitude about 41°, and about 270 b. c. But the appearances described were never to be seen in that latitude, nor in any latitude in that age. Thus, he mentions that the head of the Dragon—that is, Etamin (γ Draconis)—and the waist of Cepheus—that is, Ficares (β Cephei)—are on the circle of perpetual apparition. Now, this was true only in the latitude of Babylon, 22½°; N., about 2200 b. c. He also describes pretty carefully the most southerly stars seen, mentioning the star now called the Peacock's eye (α Pavonis), as well as Canopus (α Argus), but saying that there are no bright stars between the latter and Cetus, so that α Phœnicis must have been invisible. Now these descriptions will suit only a station of latitude 32° N. to 35° N., and an epoch between 1500 b. c. and 2200 b. c. Aratus also describes the courses of the tropics among the stars. That of the tropic of Cancer best agrees with 2200 b. c., that of the tropic of Capricorn with 2000 b. c. The equator is also described in a manner which answers perfectly to 2100 b. c. Finally, there are twelve descriptions of the appearances of the heavens at the rising of each of the constellations of the zodiac, which, while not very decisive, are not in positive disagreement with the other indications. But there is no doubt that the early part of the poem (written long before the precession of the equinoxes was suspected) copies indirectly early Accadian records. The zodiac was, therefore, formed before 2000 b. c. It cannot have been formed very long before, since there is much reason to believe that the constellation Aries either contained the sun or rose just before the sun at the time of the vernal equinox. Now, it was about 2100 b. c. when the vernal equinox fell upon the last point of Arics, and the other constellations were in similar mean positions. Some highly competent writers, however, regard the first formation of the zodiac as vastly more ancient. Several of the ancient constellation figures have a remarkably Babylonian character, as Virgo, Capricornus, Sagittarius, Centaurus, and Ophiuchus; one (Cepheus) has a barbarian name; and nearly all may be explained from Babylonian mythology. Two at least of the symbols for signs, those of Gemini and Scorpio, much resemble the Babylonian ideographs for the corresponding months. Yet the origin of the Bears, Auriga, Pegasus, Lyra, and Corona was probably not Babylonian. Moreover, certain subjects of common Babylonian fable, such as the tree of life, are not found among the constellations. It is noticeable that it was about 2300 b. c. that He and Ho are said to have reformed the Chinese calendar and divided the heavens into seasons; but the attempt to connect our constellations with the Chinese asterisms has conspicuously failed. The figures of the Chinese zodiac are Tiger, Rabbit, Dragon, Serpent, Horse, Ram, Ape, Cock, Dog, Pig, Rat, Bull. The zodiac was marked out by the ancients as distinct from the rest of the heavens because the apparent places of the sun, moon, and the planets known to them were always within it. This, however, does not hold good of all the newly discovered planetoids. See cuts under constellations named.
3. n. Figuratively, a round or circuit; a zone; a complete course.
4. n. In heraldry, a bearing representing a part of the imaginary zodiacal circle, forming an arched bend or bend sinister, and with several of the signs upon it, the number being specified in the blazon.

Wiktionary

1. n. astrology The belt-like region of the celestial sphere approximately eight degrees north and south of the ecliptic, which thousands of years ago included the apparent path of the sun, moon, and planets.
2. n. astrology The twelve equal divisions of the astrological zodiacal region into signs, or houses, of the zodiac, each sign named after a constellation in this region.
3. n. astronomy The belt-like region of the celestial sphere corresponding to the apparent path of the sun over the course of a year, the ecliptic.
4. n. countable A circle decorated with the signs of the zodiac.
5. n. Any of various astrological systems considered similar to the above.

GNU Webster's 1913

1. n. An imaginary belt in the heavens, 16° or 18° broad, in the middle of which is the ecliptic, or sun's path. It comprises the twelve constellations, which one constituted, and from which were named, the twelve signs of the zodiac.
2. n. A figure representing the signs, symbols, and constellations of the zodiac.
3. n. Poetic & R. A girdle; a belt.

WordNet 3.0

1. n. (astrology) a circular diagram representing the 12 zodiacal constellations and showing their signs
2. n. a belt-shaped region in the heavens on either side to the ecliptic; divided into 12 constellations or signs for astrological purposes