The authors agree that the surname was formed from a Germanic given name whose second element is wini ("friend, companion").

A. Bongioanni records the name as documented in the forms Aldawin, or as a metathesis of Adalwin. He notes that in the first case the root is alt or ald ("old"), and in the second, adal ("noble"). He documents the name as Aldoinus in a document from Nonantola of the year 752.

V. Blunda, for the Sicilian variant, derives it from the Germanic compound Alda Wini ("old friend" or "aged companion"), formed from alda ("old") and wini ("friend, companion in arms"). He notes that in Lombard culture the wini was the comrade bound by an oath of mutual loyalty, a central figure of the Germanic comitatus described by Tacitus. He adds that the variant Altovino reflects the phonetics of southern Italy with vowel dissimilation.