F. Miranda proposes three possible origins for this surname. The first links it to the Greek pyrros ('of fire'), used as a byname alluding to the hair colour of the first bearer. The second connects it with dialectal modifications of the personal name Pietro. The third, proper to southern surnames, derives it from the Sicilian piro, with the meaning of 'pear'. Miranda places its greatest diffusion in Calabria, Sicily and Campania, with a smaller presence in Apulia, Lombardy, Tuscany, Lazio, Emilia-Romagna, Piedmont, Basilicata, Liguria and Sardinia.

V. Blunda concentrates on the Sicilian origin and reinforces the hypothesis of the dialect term pìro ('pear'), noting that the name of the fruit was used as a nickname for its connotations of shape and sweetness. Blunda specifies that it could have been applied to a person of rounded features or engaged in the pear trade, thus adding a functional and descriptive nuance.