LAT

Lewis Short

(adjective) : Pŏsīdes, ae, m.
* A freedman of the emperor Claudius, Suet. Claud. 28; Juv. 14, 91.—Hence, Pŏsīdĭānus, a, um, , Posidian: aquae,Plin. 31, 2, 2, § 5.
Charlton T. Lewis, Charles Short, A Latin Dictionary

PIR

Male Personal name
Confirmed occurences in the Roman Empire:
Prosopographia Imperii Romani
memory