E. Rossoni places this surname in the area comprised between Verona and Mantua, and proposes that it derives from a nickname based on the term ganzo. This word would come from the Germanic gans ("young") or from the late Latin ganzia, in turn derived from ganea ("place of carousing"), in allusion to the free-and-easy behaviour of the founding ancestor.

F. De Laurentiis agrees in noting ganzo as the base of the surname, although he approaches it from a different perspective: he links it to the medieval Latin giangia ("harlot"), which would go back to the classical Latin ganeo ("tavern-keeper, owner of a tavern"). From this reading, the original nickname would have designated people of questionable conduct or reputation in their environment.