[am.phib.i.an] n [ultim. fr. Gk amphibion amphibious being, fr. neut. of amphibios] (1835) 1: an amphibious organism; esp: any of a class (Amphibia) of cold-blooded vertebrates (as frogs, toads, or salamanders) intermediate in many characters between fishes and reptiles and having gilled aquatic larvae and air-breathing adults
2: an airplane designed to take off from and land on either land or water -- amphibian adj