A dryad is a tree nymph or tree spirit in Greek mythology. Drys signifies "oak" in Greek, and dryads are specifically the nymphs of oak trees, but the term has come to be used for tree nymphs in general, or human-tree hybrids in fantasy. They were normally considered to be very shy creatures except around the goddess Artemis, who was known to be a friend to most nymphs.
