A. Bongioanni considers that this surname is of Germanic origin, derived from the root nord ("north"), and that its correct pronunciation is supported by Treviso documents where it appears under the forms Nordius, Nordilius and Nordiglus. He notes that today it is a surname proper to Veneto.

E. Rossoni proposes that it derives from the medieval name of Frankish origin Nordius, obtained from the Latinization of an abbreviated form of the name Nordberth. He documents it in the 14th century with the Treviso abbot Nordius and in a document of 1415 in Friuli. Rossoni also mentions that, according to another source, it could derive from the Germanic personal names Nordi, Nordila or Nordhari. Its fixing as a surname is documented at Chioggia, in the Venice area, in the 16th century, with the notary Matteo Nordio.