zodiac Look up zodiac at Dictionary.com
late 14c., from O.Fr. zodiaque, from L. zodiacus "zodiac," from Gk. zodiakos (kyklos) "zodiac (circle)," lit. "circle of little animals," from zodiaion, dim. of zoion "animal" (see zoo). [Libra is not an animal, but it was not a zodiac constellation to the Greeks, who reckoned 11 but counted Scorpio and its claws (including what is now Libra) as a "double constellation." Libra was figured back in by the Romans.] In O.E. the zodiac was twelf tacna "the twelve signs," and in M.E. also Our Ladye's Waye and the Girdle of the Sky.