noun

1. a beltlike zone in the sky extending for about eight degrees on either side of the apparent path of the sun and including the paths of the moon and the principal planets: it is divided into twelve equal parts, or signs, each named for a different constellation
2. a figure or diagram representing the zodiac and its signs: used in astrology
3. Rare a circle or circuit

Etymology: ME zodiak < MFr zodiaque < L zodiacus, zodiac < Gr zōdiakos (kyklos), zodiac (circle), lit., circle of animals < zōidion, dim. of zōion, animal: see bio-