adj. & n.
--adj.
1. living both on land and in water.
2 Zool. of or relating to the class Amphibia.
3 (of a vehicle) able to operate on land and water.
--n.
1. Zool. any vertebrate of the class Amphibia, with a life history of an aquatic gill-breathing larval stage followed by a terrestrial lung-breathing adult stage, including frogs, toads, newts, and salamanders.
2 (in general use) a creature living both on land and in water.
3 an amphibian vehicle.