Naiad

[ney-ad, -uh d, nahy-] /ˈneɪ æd, -əd, ˈnaɪ-/

noun, plural naiads, naiades
[ney-uh-deez, nahy-] /ˈneɪ əˌdiz, ˈnaɪ-/ (Show IPA)
1.
(sometimes initial capital letter) Classical Mythology. any of a class of nymphs presiding over rivers and springs.
2.
the juvenile form of the dragonfly, damselfly, or mayfly.
3.
a female swimmer, especially an expert one.
4.
Botany. a plant of the genus Najas, having narrow leaves and solitary flowers.
5.
Entomology. an aquatic nymph.
6.
a freshwater mussel.
/ˈnaɪæd/
noun (pl) -ads, -ades (-əˌdiːz)
1.
(Greek myth) a nymph dwelling in a lake, river, spring, or fountain
2.
the aquatic larva of the dragonfly, mayfly, and related insects
3.
Also called water nymph. any monocotyledonous submerged aquatic plant of the genus Naias (or Najas), having narrow leaves and small flowers: family Naiadaceae (or Najadaceae)
4.
any of certain freshwater mussels of the genus Unio See mussel (sense 2)
n.

“water nymph,” c.1600, from Latin Nais, Naias (genitive naiadis), from Greek Naias (plural Naiades) “river nymph,” from naiein “to flow,” from PIE *naw-yo-, suffixed form of root *(s)nau- “to swim, flow, let flow” (see nutriment). Dryden used the Latin singular form Nais, and the plural Naiades is attested in English from late 14c.