(formed of ἀμα, together, and δρυς, dryad, of δρύς, oak), in antiquity, certain fabulous deities revered among the ancient heathens, and believed to preside over woods and forests, and to be inclosed under the bark of oaks. The hamadryades were supposed to live and die with the trees they were attached to; as is observed by Servius on Virgil, Eclog. x. ver. 62. after Minetimachus, the scholiast of Apollonius, &c. who mentions other traditions relating thereto.

The poets, however, frequently confound the Hamadryads with the Naiads, Napeae, and rural nymphs in general; witness Catullus, Carm. lxviii. ver. 23. Ovid, Fast. iv. 229. Met. i. ver. 695. iv. ver. 628. Propertius, Eleg. xx. 32. Virg. Ec. x. ver. 64. Georg. iv. ver. 382, 383. Feitus calls them Quercetulane, as being infused or sprung from oaks. An ancient poet, Pherecius, in Athenaeus, lib. iii. calls the vine, fig-tree, and other fruit-trees, hamadryades, from the name of their mother the oak.

This common idea among the ancients, of nymphs or intellectual beings annexed to trees, will account for their worshipping of trees; as we find they did, not only from their poets but their historians. Livy speaks of an ambassador's addressing himself to an old oak, as to an intelligent person and a divinity, lib. iii. § 25.