E. Rossoni identifies it as a typically Lombard surname of the Bergamo area —especially of Verdello, Verdellino, Bergamo and Dalmine—, with areas also in Vailate (Cremona area).

Rossoni proposes that it would be a demonymic form of place names such as Regona, in the Brescia or Crema areas. These, in turn, would derive from the Lombard dialect word reeguna, which designates the terrain subject to periodic flooding because it is located beside a watercourse.

It is considered, along similar lines, that the surname comes from the medieval word of Celtic origin regona, which indicates a marshy terrain beside a watercourse. More probably, however, it is connected to the dialect regunà/dragunà ("to slide"), derived in turn from a word of Latin origin.