The authors do not agree on the origin of this surname. F. De Laurentiis notes that the base is various jocular nicknames and trade names formed from braga, a Venetan dialectal term that designates men's trousers. He also indicates that in some cases the surname may derive from the place name Braga, a locality near Ceregnano, in the province of Rovigo.

V. Blunda proposes, on the other hand, a completely different origin for the Sicilian variant: he would derive it from the Greek blàcos, a term that designated the Vlach, that is, one originating from Wallachia. According to Blunda, the Sicilian surname would fix the Italianized spelling of that term, with the l resolved into r. The author relates it to the surname Blacco, recorded by himself in another entry.

These are, therefore, two independent etymologies that would correspond to different geographical origins: the Venetan one, linked to the dialectal lexicon and to the toponymy of the Rovigo area, and the Sicilian one, of Greek root and linked to the presence of population of Balkan origin in Sicily.