amphibian

[am-fib-ee-uhn]

noun

1. 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.

2. an amphibious plant.

3. an airplane designed for taking off from and landing on both land and water.

4. 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

1. belonging or pertaining to the Amphibia.

2. amphibious.

amphibian

/ æmˈfɪbɪən /

noun

1. 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

2. a type of aircraft able to land and take off from both water and land

3. any vehicle able to travel on both water and land

adjective

1. another word for amphibious

2. of, relating to, or belonging to the class Amphibia

amphibian

1. 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.

Other Word Forms

• nonamphibian adjective

Word History and Origins

Origin of amphibian¹

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

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.

Example Sentences

From amphibians and reptiles to birds and mammals, no biological class is immune.

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They show that structures analogous to the superior colliculus -- found in fish, amphibians, reptiles, birds, and mammals -- share a common purpose: merging sensory and motor information to guide gaze and attention.

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These bats are known to feed on small túngara frogs, so researchers expected the recordings to show many quick captures of these tiny amphibians.

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But the relative lack of rain this spring and summer could lead to lower insect and amphibian numbers next year since eggs may not be laid and wetland areas are drying up.

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Insect loss is linked to intensive agriculture, pesticides and climate change, with far-reaching consequences for the many birds, amphibians, bats and reptiles that rely on insects for food.

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Related Words

• frog 
• salamander 
• toad