mam·​mal | \ ˈma-məl How to pronounce mammal (audio) \

Definition of mammal

: any of a class (Mammalia) of warm-blooded higher vertebrates (such as placentals, marsupials, or monotremes) that nourish their young with milk secreted by mammary glands, have the skin usually more or less covered with hair, and include humans

Other Words from mammal

mammalian \ mə-​ˈmā-​lē-​ən How to pronounce mammal (audio) , ma-​ \ adjective or noun
mammal-like \ ˈma-​məl-​ˌlīk How to pronounce mammal (audio) \ or less commonly mammallike adjective
mammal-like behavior mammallike reptiles

Examples of mammal in a Sentence

Human beings, dogs, and cats are all mammals.
Recent Examples on the Web Not a single mammal, bird, fish, reptile or amphibian species, or none of the spiders, worms, crabs, snails and other gastropods are represented in these costs. Sahana Ghosh, Quartz, 10 May 2022 The open country is prime hunting ground for hawks that wait atop saguaros, ready to make a meal of any reptile, small mammal or bird that shows itself. Mare Czinar, The Arizona Republic, 30 Dec. 2021 Back then, the series was a vaguely dystopian look at a world where every mammal with a Y chromosome mysteriously dies, leaving roughly half the population of Earth to pick up the pieces. Angela Watercutter, Wired, 22 Oct. 2021 The team started with North America’s largest mammal since the free-ranging bison spend much of their time grazing, keeping certain plants in check and allowing others to flourish. Erika Page, The Christian Science Monitor, 4 Apr. 2022 Scientists think the ancient mammal was a basilosaurus, part of the aquatic cetacean family, whose contemporary descendents include whales, dolphins and porpoises. NBC News, 18 Mar. 2022 As the national mammal of the United States and a central part of many Native American traditions, the animal carries significance far beyond its small share of the agricultural market. New York Times, 12 Mar. 2022 The largest specimens represent animals about 66 feet long, the largest mammal that had ever lived until modern whale families began to evolve. Riley Black, Smithsonian Magazine, 3 Jan. 2022 The voracious appetite of the invasive Burmese python is causing Florida’s mammal and bird populations to plummet. New York Times, 28 Mar. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'mammal.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of mammal

1811, in the meaning defined above

History and Etymology for mammal

from base of New Latin Mammalia (Linnaeus), class name, noun derivative from neuter plural of mammālis, from Latin mamma "breast, udder" + -ālis -al entry 1 — more at mamma

Learn More About mammal

Dictionary Entries Near mammal

mamma's boy



See More Nearby Entries 

Statistics for mammal

Last Updated

14 May 2022

Cite this Entry

“Mammal.” Dictionary, Merriam-Webster, Accessed 24 May. 2022.

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

More Definitions for mammal


mam·​mal | \ ˈma-məl How to pronounce mammal (audio) \

Kids Definition of mammal

: a warm-blooded animal (as a dog, mouse, bear, whale, or human being) with a backbone that feeds its young with milk produced by the mother and has skin usually more or less covered with hair


mam·​mal | \ ˈmam-əl How to pronounce mammal (audio) \

Medical Definition of mammal

: any of the higher vertebrate animals comprising the class Mammalia

Other Words from mammal

mammalian \ mə-​ˈmā-​lē-​ən, ma-​ How to pronounce mammal (audio) \ adjective or noun

More from Merriam-Webster on mammal

Nglish: Translation of mammal for Spanish Speakers

Britannica English: Translation of mammal for Arabic Speakers Encyclopedia article about mammal


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!