[1] The nomen Cestius seems to be derived from the cognomen Cestus, referring to an open-fingered boxing glove, or to a girdle.
[4] However, the name might also indicate that some of the Cestii claimed descent from the great patrician house of the Sulpicii, who had long used this surname.
The cognomina Gallus, Macedonicus, Proculus, and Severus were probably personal surnames, as was Pius, a rhetorician and a native of Smyrna, who was perhaps a freedman of the gens.
Macedonicus alluded to the military service of one of the Cestii in Macedonia, while Proculus was an old praenomen that came to be used as a surname in many families.
Severus was a common surname meaning "grave, serious," or "severe", while Pius referred to a person known for being dutiful or pious.