A mononymous person is an individual who is known and addressed by a , or "single name". In some cases, that name has been selected by the individual, who may have originally been given a ("multiple name"). In other cases, it has been determined by the custom of the country or by some interested segment. In the case of historical figures, it may be the only one of the individual's names that has survived and is still known today.
The structure of persons' names has varied across time and geography. In some societies, individuals have been mononymous, receiving only a single name. Alulim, first king of Sumer, is one of the earliest names known; Narmer, an ancient Egyptian pharaoh, is another. Later, Biblical names were typically mononymous, as were names in the surrounding cultures of the Fertile Crescent. Ancient Greek names also follow the pattern, with epithets (reminding of second names) only used to avoid confusion, as in the case of Zeno the Stoic and Zeno of Elea; likewise, patronymics or other biographic details (such as city of origin, or another city the individual was associated with, borough, occupation) were used to specify whom one was talking about, but these details were not considered part of the name.
A departure from this custom occurred, for example, among the Romans, who by the Republican period and throughout the Imperial period used multiple names: a male citizen's name (the use being mostly typical of the upper class, while plebeians would usually have only two names) comprised three parts, praenomen (given name), nomen (clan name) and cognomen (family line within the clan) — the nomen and cognomen being virtually always hereditary.