amphibian Definition

amphibian
noun

1. zool.
Any of numerous cold-blooded vertebrates belonging to the class amphibia, eg frogs, toads and newts, the adults of which live partly or entirely on land but return to water to lay their eggs, which hatch to form fish-like larvae or tadpoles that breathe by means of gills.
2. A vehicle that can operate both on land and in water.

adj

1. Referring or relating to these kinds of animals or vehicles.

Etymology: 17c: from Greek amphibia creatures that live in both environments, from amphi both + bios life.