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

Cameroon Death Lake Lake Nyos in Cameroon, Central Africa; deadly carbon dioxide gas suddenly burst forth in 1986, creating a toxic cloud that killed nearly 1,800 people, 3,000 cattle, and countless domestic and wild animals, birds, amphibians, reptiles, and insects. —Literary Hub, 22 Oct. 2025

But while some amphibians face existential threats to their existence, others are being discovered for the very first time. —Irene Wright, Miami Herald, 21 Oct. 2025

Per the study, the female life expectancy advantage is only consistent in mammals, whereas in birds, amphibians and insects, males tend to live longer. —Rachel Raposas, PEOPLE, 7 Oct. 2025

In addition to snakes, the area is home to 66 percent of Illinois‘ amphibians and over 90 percent of the state’s mammals. —Owen Clarke, Outside, 19 Sep. 2025

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

1749, in the meaning defined at sense 1

Rhymes for amphibian

• caribbean
• libyan

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