The consulted works concur in tracing this surname to the word mòtta, referring to a rise or elevation in the ground. E. De Felice defines it precisely as "a rise in the ground; a large accumulation of stones, rubble or sand," and observes that the corresponding toponymic type is widespread across both northern and southern Italy, with greater frequency in Lombardy, Calabria, and Sicily. E. Rossoni adds that this archaic word gave its name to numerous localities distributed throughout the peninsula, among them Motta Baluffi in the area of Cremona, Motta Visconti in the area of Milan, Motta Camastra in the area of Messina, Motta S. Anastasia in the area of Catania, Motta S. Giovanni in the area of Reggio Calabria, and Motta S. Lucia in the area of Catanzaro, among many others. The surname thus arose as a toponymic designation for those who came from or lived near one of these places.

R. Brondolo pursues the etymology further back, proposing a pre-Latin root, the term mutt, meaning "blunt," as the base from which this extensive place-name tradition developed. Brondolo also notes that in French toponymy the equivalent term evolved in meaning from a simple height to a hill bearing a castle, and that its roots may predate Late Latin altogether. Surnames in Italy similarly identifies a Gaulish origin, describing it as a word meaning "hill," which aligns broadly with the pre-Latin hypothesis advanced by Brondolo.

V. Blunda records a distinct and exclusively Sicilian interpretive tradition. According to this reading, the surname derives from the dialect use of mòtta in the sense of "deceased woman" or "dead woman," which would have served as a byname identifying the descendants of a dead mother or grandmother before eventually becoming a hereditary family surname. Blunda presents this as a separate development, independent of the toponymic origin accepted by the other scholars.