(n.) One of a class of fabled female water spirits who might receive a human soul by intermarrying with a mortal.

Davy Davy Jones Neptune Nereid Oceanid Oceanus Poseidon Thetis Triton elemental elemental spirit fresh-water nymph gnome kelpie limniad man fish mermaid merman naiad nix nixie ocean nymph salamander sea nymph sea-maid sea-maiden siren sylph water god water spirit water sprite