ABRACADABRA

Abracadabra was considered as a magic word and historically was believed to have healing powers when inscribed on an amulet. The word is thought to have its origin in the Aramaic language, in which abra means "to create" and cadabra  which means "as I say", providing a translation of abracadabra as "create as I say", thus its use in magic.

The first known mention of the word was in the second century AD in a book called Liber Medicinalis by Quintus Serenus Sammonicus, physician to the Roman emperor Caracalla, who prescribed that malaria sufferers wear an amulet containing the word written in the form of a triangle:

This diminishes the hold over the patient of the spirit of the disease. Other Roman emperors, including Geta and Alexander Severus, were followers of the medical teachings of Serenus Sammonicus and may have used the incantation as well.

The Puritan minister Increase Mather dismissed the word as bereft of power. But Aleister Crowley regarded it as possessing great power; he said its true form is abrahadabra.

The word is now commonly used as an incantation by stage magicians. A variation of the word, 'Avada Kedavra' is used as the death spell in Harry Potter series.