plural noun
Rep·​til·​ia | \ repˈtilēə, -lyə \

Definition of Reptilia

: a class of Vertebrata comprising air-breathing animals that have lungs but never gills, usually a three-chambered heart, two aortic arches from which the systemic arteries arise, a bony skeleton in which the skull articulates with the vertebral column by a single occipital condyle, the vertebrae gastrocentral, and the compound mandible articulate with the skull through a quadrate bone, that lack hair or feathers and have the skin more or less covered with horny epidermal plates or scales and relatively free from glands, that are known since the Carboniferous and as the dominant form of life in the Mesozoic, and that are represented in the recent fauna by the snakes and lizards, the turtles, the loricates, and the aberrant tuatara — see cotylosauria , loricata , mesosauria , pelycosauria , pterosauria , rhynchocephalia, squamata , testudinata , therapsida

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

History and Etymology for Reptilia

New Latin, from Late Latin, plural of reptile

Learn More About Reptilia

Dictionary Entries Near Reptilia




See More Nearby Entries 

Statistics for Reptilia

Cite this Entry

“Reptilia.” Dictionary, Merriam-Webster, Accessed 3 Jul. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon


Test Your Vocabulary

Name That Food

  • a-light
  • Name these cookies!
True or False

Test your knowledge - and maybe learn something along the way.

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!