A. Bongioanni notes that it is a surname of Roman origin, which was probably at first a personal name imposed on those who were born of parents of advanced age, derived from the Latin senex ("old"). He adds, nonetheless, that the Lombard variant of the surname derives from the place name Seniga, in the Brescia area.

E. Rossoni links it to the Latin name Seneca, illustrated by the celebrated philosopher and dramatist Lucius Annaeus Seneca, tutor and political adviser of the emperor Nero. The surname presents independent lines of origin (ceppi) in different zones: Rome and the Latina area, as well as nuclei in the Naples, Benevento and Caserta areas.