E. Rossoni considers that this surname is very rare and typical of the Salerno area, and that it would derive from the aphaeresis of the place name Matierno, that is, through the suppression of the initial syllable of that place name.

V. Blunda, on the other hand, proposes a different origin and places it in Sicily. According to this perspective, the surname would come from the Sicilian dialectal word tèrnu, meaning "ternary" or "of three elements", which designates that which is divided into three parts. As a surname, it would have arisen from a nickname applied to a person who occupied the third place in their family or who was associated in some way with triple combinations or groupings.

Both hypotheses are independent of each other and point to different geographical and etymological origins, which suggests that the surname presents independent stems of origin (ceppi) arisen in different regions of southern Italy without a direct relation between them.