A water nymph; one of the lower female divinities, fabled to preside over some body of fresh water, as a lake, river, brook, or fountain.
- Greek Mythology One of the nymphs who lived in and presided over brooks, springs, and fountains.
- The satellite of Neptune that is closest to the planet.
- The aquatic nymph of certain insects, such as the mayfly, damselfly, or dragonfly.
- An aquatic plant of the genus Naias.