S. Vannozzi explains that this is a surname of patronymic origin, arisen from the transformation into a surname of the proper name of the founding ancestor. In the documented case, that name was Angelo, which evolved through the dialectal forms Anzeolo, Zeolo, Zeolla, up to Zeoli and Zeuli. According to Vannozzi, the surname is typical of the provinces of Campobasso, in Molise, and of Benevento, in Campania, with its epicentre in Santa Croce del Sannio.

Vannozzi also notes that in the neighbouring municipality of Morcone, likewise in the province of Benevento, there is a place name called Zeoli, derived precisely from a family of the same name that had properties there. E. Rossoni, for his part, proposes precisely that place name of Morcone as a possible origin of the surname, although without developing the evolutionary chain of the name that Vannozzi provides.