mammal

noun mam·mal \ ˈma-məl \

|Updated on: 9 Jun 2018

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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mammalian

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

See mammal defined for English-language learners

See mammal defined for kids

Examples of mammal in a Sentence

Human beings, dogs, and cats are all mammals.

Recent Examples of mammal from the Web

Since this discovery, scientists didn't know much about the early stages of lizard and snake evolution, even though there are twice as many different species of them as mammals, the University of Bristol notes.

— ashley may, USA TODAY, "World's oldest lizard fossil reveals new evolutionary clues about reptiles, scientists say," 31 May 2018
Brisket This is the only item that came from a mammal that didn’t quite wow us.

— andy staples, SI.com, "Nick Saban Doesn't Make the Transfer Rules; He Just Wants the SEC to Agree on Them," 29 May 2018
Beachgoers were startled to find a dead marine mammal washed up in Manchester-by-the-Sea Thursday afternoon, officials said.

— elise takahama, BostonGlobe.com, "Dead porpoise washes up at Singing Beach in Manchester-by-the-Sea," 25 May 2018
The study also notes that the average weight of a mammal would drop sharply to just 6 pounds, down from 37 pounds currently and 216 pounds 125,000 years ago.

— chris ciaccia, Fox News, "Humans are killing off large mammals at an alarming rate, study finds," 20 Apr. 2018
The number of mammal and bird species varies from place to place, but these groups of vertebrates still span much of the world.

— mark fischetti, Scientific American, "Reptiles Are Concentrated in Specific Locations, Often Unprotected," 1 Apr. 2018
Hunt for Rainy-Day Critters Catching a large mammal like a bear or elk in the rain can make for an exceptional photograph.

— sami emory, Outside Online, "Embrace the Rain," 27 Mar. 2018
The sabre is a fencing weapon, not a mammal, but above the crossed swords in the NHL team’s logo is an unmistakable buffalo.

— ben cohen, WSJ, "Buffalo Is the NCAA Tournament’s Cinderella. Why Aren’t They the Buffalo?," 16 Mar. 2018
Gabriel’s studies in 2012, 2013 and 2015 linked the deaths of fishers, a weasel-like mammal, to them ingesting rat poison at clandestine grows.

— ryan sabalow and dale kasler, sacbee, "California’s timber industry was sacrificed for the spotted owl. Now pot farms pose new threat," 11 Jan. 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.

Origin and Etymology of mammal

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

NEW! Time Traveler

First Known Use: 1813

in the meaning defined above

See Words from the same year

Other Mammals Terms

dormouse, dugong, gibbon, grimalkin, sable, stoat, ungulate, vole

MAMMAL Defined for English Language Learners

mammal

noun

Definition of mammal for English Language Learners

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

MAMMAL Defined for Kids

mammal

noun mam·mal \ ˈma-məl \

Definition of mammal for Students

: 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