: a class of subphylum Vertebrata comprising forms (as the frogs, toads, newts, and salamanders) that are intermediate in many respects between fishes and reptiles, are cold-blooded with nucleated red blood cells and a 3-chambered heart, and that have gilled aquatic larvae and air-breathing adults
: the members of the class Amphibia
—am·phib·i·an\-ē-ən\noun or adjective
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