Nymph
Νύμφη
Young female spirits dwelling in springs, trees, and mountains.
Naiads live in the waters, Dryads in the trees, Nereids in the sea — their names divide by where they dwell.
They are not gods, but they are deathless or very long-lived. A tree's nymph vanishes when her tree dies.
Echo, Daphne, Syrinx — the heroines of some of the most famous stories are all nymphs.