The authors agree in pointing to a connection with Greek for the southern forms of the surname. G. Rohlfs studies it exclusively from that perspective: he considers it a surname of Greek-Byzantine origin, derived from the Greek ζερβός ("left-handed"), documented in Catanzaro and in the Reggio Calabria area —including localities such as Ortì and Taurianova—, as well as in the Cosenza area, in Mandatoriccio. For Rohlfs, this surname reflects the survival of the Greek lexicon in Calabrian onomastics.

E. De Felice shares the Greek base for the extreme south, where he notes that the surname could derive from a nickname related to the Modern Greek zerbós, with the same meaning of "left-handed". However, De Felice broadens the analysis considerably towards northern Italy, where the surname presents different etymons and formative processes. In that zone, the main base would be place names or derivatives of the northern equivalents of gérbido ("arid land"), such as Zerbo —present in the Genoa, Pavia, Milan and Piacenza areas—, Zerba and Zerbio in the Piacenza area, Zerbino in the Genoa area, and Zerbinate in the Ferrara area.

De Felice also considers other possible bases for the north: the Venetan and Triestine zèrbo, with the sense of "sour, acidic", or the old Ligurian zerbin, which designated the "inhabitant or native of the island of Djerba" (Tunisia). In addition, he notes the possible influence of the proper name Zerbino, diffused by the chivalric poems and in particular by the Orlando furioso of L. Ariosto, which would have favoured its transformation into a surname in certain zones.