E. Rossoni notes that the surname presents independent clusters of origin in different regions of Italy. He identifies clusters in the Milan area, in the Bari area and in the province of Rome. He proposes that it could derive from a nickname based on the word cogno —a type of barrel—, which would indicate the trade of cooper, or from a connection with the place name Cogno, in the Brescia area.

V. Blunda, on the other hand, offers an interpretation of Sicilian root. According to this author, the surname comes from the dialectal word cugnèttu, which designated a "short and chubby person". The term is linked to cugnu ("wedge, short and robust piece"), applied metaphorically to individuals of compact body and short stature. Blunda highlights that this motivation —the nickname referring to the physique through images of the craft lexicon— is especially productive in Sicilian onomastics.

Both proposals are not necessarily mutually exclusive: the route of the cooper trade and that of the physical nickname could correspond to independent clusters of origin arisen in different regions.