The authors agree that this surname derives from the Germanic given name Friedrich (also written Friederich or Frithu-Rikj), whose meaning is "powerful in peace" or "lord of concord", formed by the elements frithu (peace, truce) and rikj (power, dominion). V. Blunda notes that it is a surname of Sicilian rooting and recalls that Frederick I Barbarossa (1122–1190), emperor of the Holy Roman Empire, sustained prolonged wars against the communal cities of northern Italy and was defeated in the battle of Legnano (1176) by the Lombard League, an episode that consolidated the political autonomy of the Italian municipalities.

A. Bongioanni documents a wide network of derived forms and regional variants. The popular forms Fedrigo and Ferigo, peculiar to the Veneto, and Fidrí, of Friuli, became surnames. Among the Venetan surnames are Frigo, Fricci, Frisi, Friso, Frizzi, Fedrazzi, Ferrazzi and Ferróli; Sfriso combines a Venetan base with a Friulian impure s. From Friuli come Feruglio (in Friulian Ferúi, predominant in Feletto Umberto, near Udine) and Feruccis (today Ferrucci), a Latinized form of Fedrúz. Federzoni is peculiar to Bologna; Frizzoni, of Bergamo, is the Italianization of the Ladin Fritschun.

Bongioanni adds that analogous to the Venetan Ferrazzi are the Piedmontese Ferazzino and the Sardinian Ferracciu. Ferrúa and Frua are of Mondovì; Ferroglio, also Piedmontese, is probably a translation of frui ("little key"); Frova, of the Canavese zone, derives from früe, a word that designates cooked chestnuts (in the Valtellina ferüdi, from the Latin ferveo). For the Tuscan Ferrucci, on the other hand, he prefers an origin in Ferrante or Ferdinando. The author also mentions that Poma includes among the derivatives of Federico the surname Frichignono, peculiar to the Biella area.