- 1 Astrology a belt of the heavens within about 8° either side of the ecliptic, including all apparent positions of the sun, moon, and most familiar planets. It is divided into twelve equal divisions or signs (Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces).
The supposed significance of the movements of the sun, moon, and planets within the zodiacal band forms the basis of astrology. However, the modern constellations do not represent equal divisions of the zodiac, and the ecliptic now passes through a thirteenth (Ophiuchus). Also, owing to precession, the signs of the zodiac now roughly correspond to the constellations that bear the names of the preceding signs
late Middle English: from Old French zodiaque, via Latin from Greek zōidiakos, from zōidion 'sculptured animal figure', diminutive of zōion 'animal'