water nymph vs faery

water nymph and faery both are nouns.

Word	Noun	Adjective	Verb	Adverb
water nymph	Yes	No	No	No
faery	Yes	No	No	No

As nouns, faery is a hypernym of water nymph; that is, faery is a word with a broader meaning than water nymph:

Other hypernyms of water nymph include faerie, fairy, fay, sprite.

water nymph (noun)	faery (noun)
(Greek mythology) any nymph of the water	the enchanted realm of fairies
a fairy that inhabits water	a small being, human in form, playful and having magical powers
submerged aquatic plant having narrow leaves and small flowers; of fresh or brackish water
a water lily having large leaves and showy fragrant flowers that float on the water; of temperate and tropical regions