The authors agree that the surname derives from the term designating the bee (ape, ápa).

E. Rossoni suggests that it derives from the Italian word ape or from its dialectal variants, probably to designate beekeepers or to highlight the industriousness of the founding ancestors. He also considers possible that in some cases it derives from modifications of the name of the Appi of the Gens Appia, a family of the Gens Claudia to which the territory of the Bari area was also assigned.

V. Blunda, for the Sicilian variant, derives it from the dialectal word ápa ("bee"), formed from a zoonymic nickname. As a surname it may have originated in the trade of the beekeeper —comparable to Aparo— or as a nickname applied to an industrious and tireless person, a common motivation in Sicilian surnames based on this insect. He notes that it coexists in the island's onomastics with related forms such as Apicella ("little bee") and Lapone ("bumblebee").