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

The miracle behind Cruz’s discovery is that amphibians such as frogs, toads and salamanders rarely make it into the fossil records because of their fragile skeletons. — Ruben Vives, Los Angeles Times, 7 Aug. 2026

Within the understudied collection, Cruz found another oddball amphibian known as the Mexican burrowing toad, the only still living species from the family Rhinophrynidae. — Taylor Nicioli, CNN Money, 5 Aug. 2026

The project will provide support to recover 100 species facing imminent extinction, spanning mammals, amphibians, reptiles, birds, fish, invertebrates and plants from 30 countries in habitats ranging from oceans to volcanic plains. — Mya Copeland, Variety, 4 Aug. 2026

About those species, the project has zeroed in on some 100 that span mammals, amphibians, reptiles, birds, fish, invertebrates and plants from 30 countries that live across a range of habitats. — Chris Gardner For The Hollywood Reporter, Robb Report, 4 Aug. 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