1. relating to or characteristic of animals of the class Amphibia • Syn: amphibian • Pertains to noun: amphibia (for: amphibian), amphibia • Derivationally related forms: amphibian (for: amphibian), amphibia 2. operating or living on land and in water - amphibious vehicles - amphibious operations - amphibious troops - frogs are amphibious animals • Ant: aquatic, terrestrial • Similar to: amphibiotic, semiaquatic