‖E‐chid″na (ē̍‐kĭd″nȧ), n. [L., a viper, adder, Gr. ἔχιδνα.] 1. (Gr. Myth.) A monster, half maid and half serpent.
2. (Zoöl.) A genus of Monotremata found in Australia, Tasmania, and New Guinea. They are toothless and covered with spines; — called also porcupine ant-eater, and Australian ant-eater.