Naiad
Naiad (nā"yad; 277) , noun
[Latin naias, -adis, nais, -idis, a water nymph, Gr nai:a`s, nai:`s, from na`ein to flow: compare French naiade. Compare Naid.]
1.
(Mythology) 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.
2.
(Zoology) Any species of a tribe (Naiades) of freshwater bivalves, including Unio, Anodonta, and numerous allied genera; a river mussel.
3.
(Zool) One of a group of butterflies. See Nymph.
4.
(Botany) Any plant of the order Naiadaceae, such as eelgrass, pondweed, etc.