abracadabraab·ra·ca·dab·ra (?b?r?-k?-d?b?r?)n.1. A magical charm or incantation having the power to ward off disease or disaster.2. Foolish or unintelligible talk.interj. Used by a magician just before completing a trick or an illusion.[Late Latin magical formula of unknown origin.]Word History: The word abracadabra is first attested in a poem about medical matters attributed to the Roman author Quintus Serenus Sammonicus, who lived around the second century ad. In one of the poem’s prescriptions for magical cures, the letters of the word abracadabra are written on papyrus in an inverted triangle and worn as an amulet around the neck. The top line of letters in the triangle consists of the word abracadabra, and one letter is subtracted from the end of this word in each line below it: abracadabr, abracadab, abracada, and so forth. At last only the letter a remains to form the vertex of the triangle. As the letters disappear, so supposedly does the disease or trouble.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.abracadabra (?æbr?k??dæbr?) interja spoken formula, used esp by conjurorsn1. a word used in incantations, etc, considered to possess magic powers2. gibberish; nonsense[C17: from Latin: magical word used in certain Gnostic writings, perhaps related to Greek Abraxas; see abraxas]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014ab?ra?ca?dab?ra (?æb r? k??dæb r?) n. 1. a mystical word used in incantations, on amulets, etc., as a magical means of warding off misfortune, harm, or illness. 2. any charm or incantation using nonsensical or supposedly magical words. 3. meaningless talk; gibberish; nonsense. [1690?1700;