E. Rossoni proposes two hypotheses on the origin of this surname. The first links it to the medieval name Ghedino, of Frankish origin, traces of which would already exist in the 6th century with a chieftain of that name. The second relates it to a nickname of Lombard origin derived from the word gaida, which designated a fortified place situated near a marshy area. Rossoni notes that the surname is typical of the Bologna and Ferrara areas.

F. De Laurentiis, by contrast, proposes the name Guido as its base, and places the greatest concentration of the surname in Lombardy and Emilia-Romagna.