Nomen gentilicium

The Latin nomen gentilicium (generally simplifed as nomen) was the second or family name in the Roman system of naming convension. Originally intended to convey ones gens/family or patrilineal ancestry, the mass conversion of non-Latin stock to Roman customs and conventions found the meaning of the nomen gentilicium lost to the flood of adoption of classic Latin names by the non-Latin derived subjects which now flooded the empire via conquest or migration.

Following the Praenomen, the nomen could be followed by the embelishing cognomen and more honourary agnomen. It can also be said that the Roman nomen conforms most closely to the modern English last name (despite modern last names being regularly a direct cognomen and even sometimes being an agnomen).

Example

Despite frequent modern reference to Julius Caesar, Julius is not his first name, but rather his nomen representing his father's linage: his first name, or praenomen, is Gaius while Caesar was his cognomen.

Thus when Gaius Julius Caesar adopted his nefew in his will, Gaius Octavian Thurinus ("octavian" being his family name), he changed his nomen gentilicium to "Julius" and accepted the associated cognomen of "Caesar". But Octavian logically kept his first name/praenomen of "Gaius". It must also be noted at that time Octavian had not yet been honoured with the agnomen of "Augustus".

Etymology

Nomen, Latin, literally translates as "Name". But in light of the praenomen, the nomen should be considered as a gens/family name.

See also cognomen and agnomen.