What is "numicus"

The Numicus was a river of ancient Latium which flowed into the sea between the towns of Lavinium and Ardea. According to the mythology of Livy, Aeneas lies buried on its banks. The river is also represented in ancient texts as a river-god Numicius (Greek: "Nomikios"). As described by Ovid, at the behest of Venus, Numicus cleans Aeneas of all of his mortal parts so that he may become a god, known as Indiges.