amphibian

Etymology

From Ancient Greek ἀμφίβιον (amphíbion), from ἀμφίς (amphís, “of both kinds”) + βίος (bíos, “life”).

adj

1. Of or relating to the class Amphibia.
2. Capable of operating on both land and water amphibious.
3. (obsolete) Having two natures.

noun

1. An animal of the Amphibia; any four-legged vertebrate that does not have amniotic eggs, living both on land and in water.
2. A vehicle which can operate on land and water. See Wikipedia article on "Amphibious aircraft"