According to F. Miranda and F. De Laurentiis, Baldi is a patronymic surname derived from the Germanic root bald, meaning “brave,” “bold,” or “courageous.” The surname most likely originates from the Lombard personal name Baldus or from shortened forms of medieval Germanic names such as Ubaldo, Teobaldo, and Baldovino, all of which contain the same root associated with valor and strength.

F. De Laurentiis explains that the surname is based on the name Baldo, documented in Medieval Latin records from the 11th and 12th centuries. He notes that Baldo often functioned as a hypocoristic, or shortened form, of longer Germanic names that became well established in Italy, including Ubaldo, Tebaldo, Rambaldo, Sinibaldo, Garibaldo, and Baldovino.

V. Blunda agrees with this interpretation and emphasizes the importance of the root bald in Lombard naming traditions. He notes that it appears in numerous Germanic personal names, such as Teobaldo (“bold people”), Ubaldo (“bold mind”), and Garibaldi (“bold spear”), making it one of the most characteristic elements of the Lombard warrior onomastic tradition.

As for its distribution, F. Miranda notes that Baldi is found throughout Italy, with particularly strong concentrations in Tuscany, Emilia-Romagna, Lombardy, Piedmont, Lazio, Campania, Liguria, Veneto, Sicily, and the Marche. F. De Laurentiis also highlights a significant presence in Umbria.

Overall, Baldi is a surname derived from the medieval personal name Baldo and the Germanic root bald, preserving the meaning of “brave,” “bold,” or “courageous,” qualities highly valued in the Germanic and Lombard world.