The authors agree that the surname was formed from a medieval personal name, although they differ on its primary origin.

E. De Felice derives it from the medieval name of Germanic origin Amerio, a variant of Ademaro or Adimaro, of Frankish tradition, but re-spread in the 12th and 13th centuries by the corresponding French name Aimiers and Amier, which appears frequently in French lyric and epic poetry. He notes that it is peculiar to Liguria —and especially to Genoa— and to Piedmont.

E. Rossoni, on the other hand, derives it from the Late Latin name Amerius or the medieval Amerinus, documented in the Diplomatic Code of Medieval Lombardy in 1145.