🔼The name Nereus in the Bible
The name Nereus occurs only once in the Bible, namely at the end of Paul's letter to the Romans, where the apostle greets a number of friends, including Nereus and his sister (Romans 16:15). Nothing further in known about this Nereus apart from the legend that he was one of two martyred servants of Flavia Domitilla, niece of emperor Domitian.
But since Paul's message was illegal in Rome, it's quite likely that the people he mentions aren't real people, or else that their names are not their real, traceable names. Nereus is of course also the name of the mythological eldest son of Pontus and Gaia (the Sea and the Earth), which may actually be a colloquial phrase or else the name of some kind of movement, and also referred to by John the Revelator (Revelation 12:12).
The Greek poet Hesiod spoke of "truthful Nereus who tells no lies" (Th.233). According to Hesiod, this Nereus had two sisters, Ceto and Eurybia.
🔼Etymology of the name Nereus
The name Nereus is probably too old to be Greek, but might still be related to the noun ναρος (naros), meaning a flowing or a liquid, which derives from the verb ναω (nao), meaning to flow. And that suggests that both the name and these words might be related to the fascinating Semitic verb נהר (nahar), meaning both to flow and to shine:
The name Nereus probably means Fluvial or He Who Flows and by application He Who Shines.