Often these names were derived from foreign sources and acquired their "barbarous" nature from the magician's lack of understanding of that language.
[1] Iamblichus discusses barbarous names, warning magicians not to translate them even if their original meaning is discovered, due to the belief that the power of the names resided in their sound, not their meaning.
[1] Gemistus Pletho censored references to barbarous names (as well as Christianity) in Michael Psellos's copy of the Chaldean Oracles.
[4] The Enochian language of John Dee and Edward Kelley introduced a variety of barbarous names to modern magical practice.
[1][2] In the modern era, Aleister Crowley, like Iamblichus before him, argued that the supposed effectiveness of barbarous names rested in their utterance, not their meaning.