NEREUS (nē'rūs, Gr. Nēreus). A Roman Christian to whom the apostle Paul extended greetings (Rom.16.15). The name has been discovered in an inscription containing a listing of the emperor’s servants. Whether this is the same Nereus is uncertain.

International Standard Bible Encyclopedia (1915)

ne’-rus, ne’-re-us (Nereus): The name of a Roman Christian to whom with his sister Paul sent greetings (Ro 16:15). Nereus and the others saluted with him (Ro 16:15) formed small community or "house church." The name of the sister is not given, but the name Nereis is found on an inscription of this date containing names of the emperor’s servants (Lightfoot, Phil, 176). Among the Acta Sanctorum connected with the early church in Rome are the "Ac of Nereus and Achilleus" which call them chamberlains of Domitilla, the niece of Vespasian, and relate their influence over her in persuading her to remain a virgin.