E. Rossoni notes that this surname is typical of Sicily, with a presence in Catania, Gravina di Catania, Aci Catena, Misterbianco and Floridia (in the Syracuse area). He derives it from the Lombard and Germanic name Wardo, meaning "sentinel".

V. Blunda agrees on the Sicilian and Germanic origin, but works out the etymology more precisely: the surname would derive from the personal name Wardu, linked to the root wardu, which goes back to the idea of guard, custody and active watchfulness. This root gave rise to the Italian guardia, the Spanish guardar and the French garder, all with the Germanic military sense of armed watch. Blunda adds that, in the Lombard political organization, the function of guard to the king was an office of high prestige: the body of fideles surrounding the sovereign answered with their lives for the monarch's safety and took part in decisions of government and war.