Answer:

nereid

Answer	Crossword Clue
NEREID	Sea nymph of Greek mythology
NEREID	Mythological sea nymph
NEREID	Sea nymph

NEREID	Mythical Aegean Sea dweller
NEREID	Moon of Neptune
NEREID	Sea nymph.
NEREID	What Galatea was.
NEREID	Mythical rider of sea horses.
NEREID	Daughter of the sea god.
NEREID	Nymph.
NEREID	Amphitrite or Thetis.

NEREID	Nymph on a sea horse.
NEREID	Poseidon attendant.
NEREID	Sea-horse rider
NEREID	Thetis, e.g.
NEREID	A moon of Neptune
NEREID	Attendant on Poseidon
NEREID	Poseidon attendant
NEREID	One of Poseidon's attendants

NEREID	Reined in nymph
NEREID	Calypso, e.g.
NEREID	Neptune's third-largest moon

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.