The authors agree that this surname derives from the Latin lepus, leporis ("hare"), whether by way of the medieval name Lepus or of its Romance form lepre, and that it originally functioned as a nickname linked to physical or behavioural characteristics of the bearer.

E. Rossoni notes that the nickname could also have alluded, though improbably, to the Latin lepor, leporis, with the sense of "grace, elegance, charm". He documents the family in Piedmont, in the area of the fief of Oglianico, with records from the second half of the 14th century under the form Lepora. For Gemona, in Friuli, he cites a document of 1373 which mentions Venturinus dictus Lyeur —"hare" in Friulian—, whose descendants later appear as Filius Leporis. Throughout the 15th century and the beginning of the 16th the surname took variable forms: Lier, Lieuro, Yeur, Hiieur, Jeur, or Latinized ones such as Leporis, de Lepore, a Lepore. As for distribution, Lepore appears throughout the Italian peninsula, with the greatest presence in southern Italy, in Lazio, Abruzzo, Molise, Campania, Puglia and Basilicata.

E. Costantini confirms the derivation from the sense of "hare" as a nickname and notes that the surname is typical of Gemona, with a presence also in Buja and Tarcento, all localities of the region of Friuli-Venezia Giulia.

V. Blunda supplies the Sicilian perspective: the surname comes from the dialect word lèpuru, a direct cognate of the Italian lepre, and could have originated in a nickname applied to a person who was swift, timid or elusive, a usual motivation in the onomastics of the zoomorphic byname.