amphibian

noun

am·​phib·​i·​an am-ˈfi-bē-ən 

1

: an amphibious organism

especially : any of a class (Amphibia) of cold-blooded vertebrates (such as frogs, toads, or salamanders) intermediate in many characters between fish and reptiles and having gilled aquatic larvae and air-breathing adults

Unlike reptiles, most amphibians possess a smooth, moist skin and lay their shell-less eggs in water or wet places.

—Jeffrey P. Cohn

2

: an amphibious vehicle

especially : an airplane designed to take off from and land on either land or water

amphibian adjective

Examples of amphibian in a Sentence

Recent Examples on the Web

Once the most populous vertebrate in their mountain habitat, the wild population of these tiny amphibians had dwindled to fewer than 200 by 2021. — ABC News, 29 Sep. 2026

At the time, it was classified as Amphibamus grandiceps, another ancient amphibian already well known from the area. — Ashley Vega, PEOPLE, 29 Sep. 2026

In amphibians, chytridiomycosis causes a wide variety of symptoms including skin damage, red skin, convulsions, and eventually leads to heart failure. — Laura Baisas, Popular Science, 24 Sep. 2026

National Geographic series Africa Earth’s Wild Home has captured the elusive amphibians — and other species — on camera for television for the first time ever. — Tony Maglio, HollywoodReporter, 10 Sep. 2026

Word History

Etymology

New Latin Amphibia, taxon including frogs and salamanders (from neuter plural of amphibius amphibious) + -an entry 1

Note: As a taxon Amphibia was used as a class name already by linnaeus (Systema naturae, 10. editio, 1758, p. 196 et passim), but in a sense that included both amphibians and some reptiles. Limitation of the taxon to approximately its current meaning dates from Thomas Gray's "A Synopsis of the Genera of Reptiles and Amphibia" (Annals of Philosophy, new series vol. 10, July-December, 1825, pp.193-217) according to Darrel R. Frost, et al., "The Amphibian Tree of Life," Bulletin of the American Museum of Natural History, No. 297 (2006), p. 355. The use of both English amphibian and Latin amphibius with varying gender and number to refer to animals living on both land and sea (and in figurative senses) can be found much earlier.

First Known Use

1654, in the meaning defined at sense 1

Rhymes for amphibian

• libyan
• caribbean

Kids Definition

amphibian

noun

am·​phib·​i·​an am-ˈfib-ē-ən 

1

: any organism that is able to live both on land and in water

especially : any of a class of cold-blooded vertebrate animals (as frogs and salamanders) that in many respects are between fishes and reptiles

2

: an airplane designed to take off from and land on either land or water

amphibian adjective