G. Rohlfs proposes a Greco-Byzantine origin for this surname, documented in the region of Basilicata —in particular in the Potenza area— and in the Salento area —that is, the southernmost zone of the region of Puglia, in southern Italy. He derives it from the Greek mágeiros, with the meaning "cook", and notes that in Greece the form Mágiros survives. For Rohlfs, this surname reflects the Byzantine presence in southern Italy.

V. Blunda, by contrast, proposes a different etymology and confines the surname to Sicily. He derives it from the dialect word màiru, with the sense of "thin, lean, spare", and considers that it became a surname from a nickname referring to the slender physical build of its original bearer, a frequent motivation in the formation of bynames.

The two proposals are incompatible with each other: Rohlfs links the surname to the Greco-Byzantine heritage of southern Italy and anchors it in Basilicata and the Salento, while Blunda treats it as an exclusively Sicilian phenomenon of Romance dialect root. The surname would therefore show at least two independent clusters of origin with different etymologies according to the region considered.