The word itself is possibly a combination of sylvestris and nympha (forest and nymph), but they’re air spirits from Paracelsus’ 16th century works. Sylphs go along with undines, gnomes, and salamanders (water, earth, and fire spirits).
Some different kinds of nymphs are dryads (oak trees), oceanids (oceans), oreads (mountains), and plenty of others.














Very late response, but I was thinking back to this and realized that, to be pedantic, yeah, female lycanthropes should actually be called wifwolves, or something to that effect; a woman becoming a werewolf would include turning into a man, if the root words are taken literally.
Kinda like how female automatons should technically be gynoids, not androids, because “andro-” means “male” in Greek, like “wer-” in English, but language doesn’t always evolve neatly like that.