A. Bongioanni notes that it is a given name of uncertain etymology, especially frequent in Sardinia. He links it to the figure of a Sardinian saint, a martyr in Cagliari in the 3rd century, whose feast is celebrated on 13 February.

V. Blunda, on the other hand, proposes a Greek etymology: it would derive from efisios, a gentilic that designates the person native to Ephesus, a city of the Ionian coast of Asia Minor. According to Blunda, this designation of origin would have motivated the formation of the surname to identify families coming from that zone of the eastern Mediterranean.