mam·mal | \ˈma-məl \

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

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Other Words from mammal

mammalian \mə-ˈmā-lē-ən, ma- \ adjective or noun

Examples of mammal in a Sentence

Human beings, dogs, and cats are all mammals.

Recent Examples on the Web

In the early 2000s, the idea of using sea mammals as ocean observers seemed laughable. Kasha Patel, Smithsonian, "How Data-Gathering Seals Help Scientists Measure the Melting Antarctic," 13 July 2018 Canine transmissible venereal tumors is one of only three known kinds of cancer that can spread from a host to another mammal. Marc Daalder, ajc, "Why none of our dog breeds are native to America," 6 July 2018 Canine transmissible venereal tumors (CTVT) is one of only three known kinds of cancer that can spread from a host to another mammal. Marc Daalder, Detroit Free Press, "Dogs native to America were wiped out by Eurasian dogs," 5 July 2018 Some types of sharks have long been in the waters off western and northern Alaska, but those don't usually go after live mammals. Annie Zak, Anchorage Daily News, "Research: Sharks might be eating more northern seals and sea lions in Alaska waters," 4 July 2018 What can kill you: A fatal disease that affects only mammals. Bruce Henderson, charlotteobserver, "Be wary of these NC natural wonders this summer," 25 June 2018 Grass and grasslands hadn’t even evolved in the Cretaceous, and large mammals had yet to make their entrance. National Geographic, "Could Humans and Dinosaurs Coexist? Here's the Science.," 22 June 2018 Just ask #MPRraccoon, currently the world’s second most famous trash-eating mammal thanks to its death-defying, Twitter-enthralling climb up the side of St. Paul’s 25-story USB Plaza. Michael Andor Brodeur,, "From a flipping pancake house to an overstuffed bot," 15 June 2018 Once it gets eaten, the parasite can then lay eggs in its new mammal host, and begin its dark cycle anew. Laura Yan, Popular Mechanics, "These Brain Worms Turn Ants Into Death-Seeking Zombies," 10 June 2018

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.

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First Known Use of mammal

1813, in the meaning defined above

History and Etymology for mammal

New Latin Mammalia, from Late Latin, neuter plural of mammalis of the breast, from Latin mamma breast

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Statistics for mammal

Last Updated

29 Sep 2018

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Time Traveler for mammal

The first known use of mammal was in 1813

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English Language Learners Definition of mammal

: a type of animal that feeds milk to its young and that usually has hair or fur covering most of its skin


mam·mal | \ˈma-məl \

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 \

Medical Definition of mammal 

: any of the higher vertebrate animals comprising the class Mammalia

Other Words from mammal

mammalian \mə-ˈmā-lē-ən, ma- \ adjective or noun

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More from Merriam-Webster on mammal

Spanish Central: Translation of mammal

Nglish: Translation of mammal for Spanish Speakers

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

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