The authors agree that this surname derives from the Sicilian dialect word piràinu, which designates the wild pear tree. The tree grew spontaneously along paths and field boundaries of the rural Sicilian landscape, and the term gave rise both to the place name Piraino —a comune in the province of Messina— and to the surname itself, which can be considered a phytotoponym, that is, a name motivated by the presence of a particular type of flora in the territory.

F. Miranda notes that the surname would have originated as a nickname attributed to a first bearer who was the owner of, or an inhabitant near, a plot with wild pear trees. V. Blunda agrees with this interpretation and adds that the starting point could have been a local microtoponym later applied to a person residing beside that tree.

Miranda indicates that the surname is present in Sicily —mainly in the provinces of Palermo, Messina, Agrigento and Caltanissetta—, with an additional presence in Calabria, Lombardy, Lazio, Tuscany, Piedmont and Veneto.