The authors agree in noting that the surname presents multiple independent stems of origin (ceppi), arisen in different regions without a direct relation between them, with important differences as to the etymological origin according to the geographical zone.

For the sphere of Calabria, G. Rohlfs considers it a surname of Greek-Byzantine origin, derived from the Greek Γερμανός, meaning "Germanic". Rohlfs documents its presence in Catanzaro and Reggio Calabria, as well as in the provinces of Cosenza —specifically in Amantea— and of Reggio Calabria —in Palmi, Polistena and the Aspromonte area—, and notes that the accented form Germanò may lose the grave accent, giving rise to the form Germano.

For the Sicilian sphere, the authors present divergent positions. V. Blunda maintains that it is a surname of strictly dialectal origin, derived from the Sicilian word ggirmànu, meaning "rye" or "oats". According to Blunda, the surname belongs to a series of Sicilian surnames of cereal origin, together with Formento ("wheat") and Gariglano ("buckwheat"), and could have originated as a nickname of one who cultivated or traded in minor cereals, typical of the poor soils of the interior of the island. Blunda expressly warns that the interpretation associating the surname with the Italian germano —in the sense of "full-blood brother" or as a reference to the Germanic peoples— constitutes a false etymology.

F. Miranda, on the other hand, does not rule out any of the etymological ways and presents them as equally possible. For Miranda, the surname could derive from the Latin cognomen Germanus, meaning "brother born of the same parents" and linked to the Latin term germen ("shoot"), with a possible resonance in Christian fraternity; or else from the ethnic identifier "German", in reference to the Germanic peoples; or from the Germanic terms ger ("spear") and mann ("man"), with the sense of "armed man" or "warrior". Miranda also contemplates, at least for the stems of southern Italy, the origin in the Sicilian dialectal word ggirmanu or jrmanu, meaning "rye", "oats" or "field of rye", according to the Vocabolario Siciliano of Piccitto. Miranda documents the presence of the surname in provinces of Sicily: Messina —in fourteen localities, among them Patti, Messina and Barcellona Pozzo di Gotto—, Catania —in Belpasso, Aci Catena, Misterbianco and San Pietro Clarenza—, Enna —in Catenanuova— and Palermo.