\Ne"re*is\ (? or ?), n.; pl. {Nereides}. [L.] 1. (Class. Myth.) A Nereid. See {Nereid}. 2. (Zo["o]l.) A genus, including numerous species, of marine ch[ae]topod annelids, having a well-formed head, with two pairs of eyes, antenn[ae], four pairs of tentacles, and a protrusile pharynx, armed with a pair of hooked jaws.