Analysis of information sources in references of the Wikipedia article "Fiddle" in English language version.
The ultimate origin is obscure. The [Teutonic] word bears a singular resemblance in sound to its [medieval Latin] synonym vitula, vidula, whence [Old French] viole, Pr. viula, and (by adoption from these [languages]) [Italian], [Spanish], [Portuguese] viola: see [viol]. The supposition that the early [Romance] vidula was adopted independently in more than one [Teutonic language] would account adequately for all the [Teutonic] forms; on the other hand, *fiÞulôn- may be an [Old Teutonic] word of native etymology, although no satisfactory [Teutonic] derivation has been found.(Subscription or participating institution membership required.)
