Horne Tooke derives it from the root bar (strong), and thinks it a repetition of the savage people's own reduplicated bar-bar (very strong); but it is far more probably an imitation of the incomprehensible speech of the strangers; as, in fact, the Greeks seem rather to have applied it first to the polished Asiatic, who would have given them less the idea of strength than the Scyth or the Goth, to whose language bar belonged in the sense of force or opposition.  It is curious to observe how, in modern languages, the progeny of the Latin barbarus vary between the sense of wild cruelty and mere rude ignorance, or ill-adapted splendour. (History of Christian Names, Yonge, 1884)

BARBARIAN (Gr. barbaros), among the Greeks, as early as the time of Homer, signified one who could not speak the Greek language; and this restricted signification was not wholly obsolete even in the age of Plato, for the latter divides the entire human race into Hellenes and Barbaroi.  The origin of the word is unknown, if it be not artificially formed, on the principle of imitation, to represent a meaningless babble of sound, such as the Greeks conceived all foreign languages to be.  It first began to acquire its secondary and invidious signification at the period of the Persian wars.  The Greeks, who always exhibited a proud consciousness of their superior intellect and privileges, employed the term to designate the character of their enemies.  It then meant whatever was opposed to Greek civilization, freedom, or intelligence; but it could not yet have attained the degraded sense in which it is now used, for the Romans in the time of Plautus accepted the appellation, and called themselves Barbaroi.  Subsequently, when Rome, under Augustus, became the mistress of the world, the word was applied to all the Germanic and Scythian tribes with whom she came into contact.  In modern times, it signifies savage, uncivilized, or ignorant. (Chambers's Encyclopedia, v.1, 1888)