The authors agree that the surname derives from the Greek ánghelos, "messenger", a term which in the Christian context also designates the angel and which passed into Italian onomastics as a given name before becoming a surname. It has been the origin of the name of several male and female saints.

A. Bongioanni notes that in Tuscany the form Angiolo is more frequent, and formerly Agnolo. In Friuli the variants Agnul, Anzul and Anzil are documented, today turned into surnames. In the Cadore area, the form Andolo gave rise to the surname Dándolo. Bongioanni adds that the Turinese surname Angeloro preserves a remnant of the Latin genitive plural, comparable to expressions such as Regina Angelorum, and that Anzilotti could also derive from Lancilotto.

V. Blunda stresses the entry of the term into Sicilian onomastics by Christian route, as a Greek given name transmitted along the family line until it consolidated as a surname.