Definition of: zodiac

(zō′dē·ak) noun
1. An imaginary belt encircling the heavens and extending about 8° on each side of the ecliptic, within which are the orbits of the moon, sun, and larger planets. It is divided into twelve parts, called signs of the zodiac, which formerly corresponded to twelve constellations bearing the same names. Now, owing to the precession of the equinoxes, each constellation is in the sign that has the name next following its own.
2. Figuratively, a complete circuit; round.
3. Rare A circle or halo; also, a girdle. [<OF zodiaque <L zodiacus <Gk. (kyklos) zōdiakos (circle) of animals <zōdion a sculptured animal, dim. of zōion an animal]
—zo·di·a·cal (zō·dī′ə·kəl) adjective
SIGNS OF THE ZODIAC
Reading clockwise:
A. Vernal equinox: Aries, Taurus, Gemini.
B. Summer solstice: Cancer, Leo, Virgo.
C. Autumnal equinox: Libra. Scorpio, Sagittarius.
D. Winter solstice: Capricorn, Aquarius, Pisces.