According to Mario Bonifacio, the surname Ferluga-Felluga, which everyone affirms to be of Spanish origin, is in reality simply a Slovene patronymic surname with the augmentative suffix uga and the root Ferle, derived from the Latin Florianus, and it means "big Florian".

According to the site Retaggio, this name, which in older sources may be pronounced both Ferluga and Frluga, has its roots in a small settlement in the majestic hills of the Gorjanci mountains, in the east of Slovenia, near the border with Croatia. This zone belongs to the traditional region of Lower Carniola.

Lower Carniola (in Slovene: Dolenjska) is a historical and geographical region in the southeast of Slovenia. It forms part of the statistical region of the Lower Sava today. The region is characterised by its topography of hills and valleys, and has played an important role in Slovene history and culture.

This surname is a living testimony of the migrations, the interculturality and the family history that intertwines with the beauties of the hills of Gorjanci.

The surname Ferluga, which is the seventh most common in Trieste, a city with a rich history of migrations and a crossroads of cultures. Many Slovene families have found refuge and opportunities in Trieste over the centuries and it also branches as far as Isola d'Istria, becoming "Felluga", losing the "r". It even gave rise to the village of Ferlughi, that is, Conconello, in the province of Trieste.

The derivatives include: Ferluggia, Ferlugini, Ferlugaro, Ferlughi, Ferlughetti, Ferluggiero, Ferlugoso, Ferluglio, Ferlugiani, Ferlughini, Felluga and perhaps others.