n. In Greek myth, a wood-nymph believed to live and die with the tree to which she was attached.n. In entomology: A dryad or wood-nymph, a butterfly of the old genus Hamadryas.n. plural A group of lepidopterous insects.n. In herpetology, a large, hooded, venomous Indian serpent, Naja hamadryas or Hamadryas elaps, now Ophiophagus elaps. It is related to the cobra.n. In mammalogy, a large Abyssinian baboon, Cynocephalus hamadryas, with long mane and whiskers and tufted tail. Also called hebe.