The surname Bombonato and its variants —such as Bombonati— are peculiar to Lombardy, with a more limited diffusion in neighbouring regions. According to E. De Felice, its origin lies in the medieval name Bombonato, formed from the element bon- ("good") and the name Bonato, derived in turn from Bono. It is, therefore, a "reduplicated" or tautological auspicious name, which reinforces the idea of goodness ("good and good"), probably arisen at a time when the awareness of the original meaning of Bonato had already been lost.

Along the same lines, F. De Laurentiis confirms both the Lombard location of the surname and its base in this compound medieval name. He also highlights that Bono or Bon was a personal name spread among Lombards and Franks, derived from the vulgar adjective "good", associated with qualities of character and positive values. This interpretation reinforces the auspicious character of the surname, which expressed a favourable wish or quality in its bearer.

For his part, E. Rossoni proposes a derivation from the medieval name Bonattus, reinforced with Bonus in forms such as Bonus Bonattus, documented in medieval texts. He also provides data on its distribution: Bombonati presents clusters in the Milan area and in the Rovigo area, while Bombonato is concentrated between Milan and Bergamo, with another focus in the province of Rovigo. Taken together, the various interpretations agree in pointing to a medieval origin linked to names of good omen, with a linguistic evolution that reinforces and multiplies their positive meaning.