According to E. Rossoni, the surname Zavagli would derive from nicknames formed from the dialectal term zavaj ("stumble"), possibly applied to persons with speech difficulties, such as stammering, which would explain its use as an identifying nickname. In southern Italy, however, he proposes a different interpretation: it could derive from the term of Greek origin zabai, pronounced zavaj, meaning "weapon of war", which would indicate an origin linked to ancestors related to the military sphere.

For his part, F. De Laurentiis places the origin in the Emilian sphere, linking it with nicknames derived from zavaglio ("bavaglio", that is, "muzzle" or "gag"), applied to persons who did not speak, could not speak or had to keep silent. In the Ferrara area, he adds another possible interpretation: an ironic or derogatory nickname derived from the dialectal term zavai, meaning "useless object", which reinforces the expressive and popular character of this type of surname.