Nā'iad, n.

noun

(nā'yad) (Synop., § 130), n. [Lat. naïas, naïs, Gr. ναϊάς, ναῖς, from νάειν, to flow; Fr. naïade, It. najade, Sp. nayade.]

(Myth.) A water nymph; a female deity, fabled to preside over rivers and springs.
(Conch.) One of a family of fresh-water bivalves, as the fresh-water clams.
(Bot.) An order of endogenous aquatic plants.