NAIS was a Naiad Nymph of the springs of the town of Pyrrhikhos (Pyrrhichus) on the Malean peninsular in Lakonia (southern Greece). She was the wife of the old rustic-god Seilenos (Silenus).
She was probably identified with the nymphe Melia.
Pausanias, Description of Greece 3. 52. 2 (trans. Jones) (Greek travelogue C2nd A.D.) :
"Inland, forty stades from the river [Skyras on the Malean peninsular in Lakonia], lies Pyrrhikhos (PYrrhichus), the name of which is said to be derived from Pyrrhos the son of Akhilleus (Achilles); according to another account Pyrrhikhos was one of the gods called Kouretes (Curetes).
Others say that Silenos came from Malea and settled here. That Silenos was brought up in Malea is clear from these words in an ode of Pindar: ‘The mighty one, the dancer, whom the mount of Malea nurtured, husband of Nais (of the Spring), Silenos.’ Not that Pindar said his name was Pyrrhikhos; that is a statement of the men of Malea. At Pyrrhikhos there is a well in the market-place, considered to be the gift of Silenos. If this were to fail, they would be short of water . . . From Pyrrhikhos the road comes down to the sea at Teuthrone . . . [They] have a spring Naia."
- Pausanias, Guide to Greece - Greek Geography C2nd AD