- Nereid⇄Nereid, noun.
1. (Greek Mythology.) any one of the fifty daughters of Nereus. The Nereids were sea nymphs who attended Poseidon (Neptune).
2. the smaller of the two moons of the planet Neptune. - nereid⇄nereid, noun.
any one of several polychaete worms with segmented bodies and distinct head parts, that live mostly along the seashore and reach a length of 5 feet or more.