Meaning

noun a belt-shaped region in the heavens on either side to the ecliptic; divided into 12 constellations or signs for astrological purposes

noun (astrology) a circular diagram representing the 12 zodiacal constellations and showing their signs

originFrom Middle English zodiak (late 14th century), from Old French zodiaque, from Latin zōdiacus, from Ancient Greek ζῳδιακός [κύκλος] (zōidiakós [kúklos], “[circle] of little animals”), from ζῴδιον (zōídion), the diminutive of ζῷον (zōîon, “animal”).

Etymology from Wiktionary, CC BY-SA 3.0