The surname Barbagianni (and related forms) originates in a composition formed by barba and Giovanni, very characteristic of medieval Italian onomastics. According to E. Rossoni, this type of surname derives from a family nickname in which barba was used with the meaning of "uncle", a figure of reference within the group. In this sense, the surname would indicate "the family of Uncle Giovanni", reflecting an extended patronymic origin based on a prominent member of the community.

For his part, G. P. Holmes proposes a different interpretation of the term barba, linking it to its Latin root with the meaning of "bearded man" or even "authoritative". From this perspective, the surname acquires a more symbolic value, interpreted as "wise John", where the idea of authority or experience is combined with the name Giovanni.

Taken together, both interpretations agree on the compound structure of the surname and on its base in the name Giovanni, but differ in the sense attributed to barba. While E. Rossoni understands it in a family and affectionate context, G. P. Holmes interprets it as a descriptive or symbolic trait, which shows the richness of possible meanings in this type of medieval formation.