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

Endangered amphibians in California include the desert slender salamander, a subterranean amphibian found in just two spots in Riverside County. —Sarah Linn, Sacbee.com, 22 Apr. 2026

Salamander Saturday is an initiative started by the Foundation for the Conservation of Salamanders to raise awareness about the amphibians, their habitats and their role in the ecosystem, according to the Forest Preserve District of Will County. —Michelle Mullins, Chicago Tribune, 21 Apr. 2026

Certain strains of the bacteria have figured out how to live happily in the kidneys of apparently healthy animals, including wildlife (such as rodents, raccoons, marine mammals and skunks, but also reptiles and amphibians) and domestic animals (such as cattle, pigs, horses, even dogs and cats). —The Washington Post, San Diego Union-Tribune, 14 Apr. 2026

Paleontologists now have direct evidence of cartilage and connective tissue in the rib cage of an early reptile, revealing how animals transitioned from amphibian-like throat pumping to the efficient lung ventilation systems that dominate terrestrial life today. —Samantha Agate, Miami Herald, 9 Apr. 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