[ 'nʌɪad ]
■ noun ( plural ~s or ~es 'nʌɪəˌdi:z )
1》 (in classical mythology) a nymph inhabiting a river, spring, or waterfall.
2》 the aquatic larva of a dragonfly, mayfly, or stonefly.
3》 an aquatic plant with narrow leaves and minute flowers. [Genus Najas .]
Origin
via L. from Gk Naias , Naiad- , from naein 'to flow'.