E. Rossoni considers this a typically Sardinian surname, derived from the vanished place name Lokeri, located in the valley of the river Tirso, in Sardinia.

V. Blunda, by contrast, places it in Sicily and proposes a Germanic root: the compound leuga harja, formed by leuga (oath, pact, ritual alliance) and harja (army, host), with the overall meaning of "host of the league" or "army of the oath". Blunda notes that collective oaths in ancient Germanic legal culture sealed military alliances between lineages and gave rise to armed confederations. The term leuga would have evolved into the Old Italian lega, preserved in the modern lega (league, alliance).

The two proposals are incompatible with each other both in their geographical origin and in their etymology, so that the surname could show independent clusters of origin (ceppi) in different regions of Italy, without either of the two hypotheses having been conclusively corroborated.