Nouns

(n)amphibian, amphibious vehiclea flat-bottomed motor vehicle that can travel on land or water
(n)amphibian, amphibious aircraftan airplane designed to take off and land on water
(n)amphibiancold-blooded vertebrate typically living on land but breeding in water; aquatic larvae undergo metamorphosis into adult form

Adjectives

(a)amphibious, amphibianrelating to or characteristic of animals of the class Amphibia