maguš

Old Persian maguš referred to a member of the Zoroastrian priestly caste, the hereditary religious specialists who maintained fire temples, performed rituals, and interpreted dreams and omens. The Magi were the priests of the Achaemenid court and were known throughout the ancient world for their astronomical knowledge, their interpretation of celestial events, and their expertise in what Greeks called mageia — the practices of the Magi.

Greek magos (from Old Persian maguš) entered Greek as a term for a Persian priest, then broadened to mean any practitioner of mysterious arts — divination, astrology, and the manipulation of unseen forces. The Greek mageia and Latin magia gave English magic. What began as a professional religious title became the word for the mysterious arts those priests practiced.

The Magi of Matthew's Gospel — the 'wise men from the East' who followed a star to Bethlehem — are identified by the Greek word magoi. The Bible does not specify their number; the tradition of three came from the three gifts (gold, frankincense, myrrh). Their names — Caspar, Melchior, and Balthasar — were attached by tradition in the 6th century CE, 500 years after the events described.

Maguš survives in English in two forms: magus for an individual sorcerer or wise man, and magic for the category of mysterious arts the Magi practiced. The Zoroastrian priests who interpreted Darius's dreams gave their professional title to the entire field of mysterious power.