amphibian

[ am-fib-ee-uh n ]
/ æmˈfɪb i ən /

noun

any cold-blooded vertebrate of the class Amphibia, comprising frogs and toads, newts and salamanders, and caecilians, the larvae being typically aquatic, breathing by gills, and the adults being typically semiterrestrial, breathing by lungs and through the moist, glandular skin.
an amphibious plant.
an airplane designed for taking off from and landing on both land and water.
Also called amtrac. a flat-bottomed, armed, military vehicle, equipped with both tracks and a rudder, that can travel either on land or in water, used chiefly for landing assault troops.

adjective

belonging or pertaining to the Amphibia.

Origin of amphibian

1630–40; < Latin amphibi(a), neuter plural of amphibius (adj.) (see amphibious) + -an

Related forms

non·am·phib·i·an, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for amphibian

British Dictionary definitions for amphibian

amphibian

/ (æmˈfɪbɪən) /

noun

any cold-blooded vertebrate of the class Amphibia, typically living on land but breeding in water. Their aquatic larvae (tadpoles) undergo metamorphosis into the adult form. The class includes the newts and salamanders, frogs and toads, and caecilians
a type of aircraft able to land and take off from both water and land
any vehicle able to travel on both water and land

adjective

another word for amphibious
of, relating to, or belonging to the class Amphibia
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for amphibian

amphibian

[ ăm-fĭbē-ən ]

A cold-blooded, smooth-skinned vertebrate of the class Amphibia. Amphibians hatch as aquatic larvae with gills and, in most species, then undergo metamorphosis into four-legged terrestrial adults with lungs for breathing air. The eggs of amphibians are fertilized externally and lack an amnion. Amphibians evolved from lobe-finned fish during the late Devonian Period and include frogs, toads, newts, salamanders, and caecilians.

Word History

Amphibians, not quite fish and not quite reptiles, were the first vertebrates to live on land. These cold-blooded animals spend their larval stage in water, breathing through their gills. In adulthood they usually live on land, using their lungs to breath air. This double life is also at the root of their name, amphibian, which, like many scientific words, derives from Greek. The Greek prefix amphi- means “both,” or “double,” and the Greek word bios means “life.” Both these elements are widely used in English scientific terminology: bios, for example, is seen in such words as biology, antibiotic, and symbiotic.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.