: 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
mammal-like
adjective
or less commonly mammallike
mammal-like behavior
mammallike reptiles
Examples of mammal in a Sentence
Human beings, dogs, and cats are all mammals.
Recent Examples on the Web
Bovine tuberculosis, a bacterial disease impact all mammals, was detected in two cattle herds in two northern Michigan counties, state officials said on Monday.
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Dejanay Booth-Singleton, CBS News, 7 Apr. 2026
When science said dinosaurs were pea-brained and cold-blooded, humans took their demise as proof of the superiority of warm, clever mammals.
—Scottie Andrew, CNN Money, 5 Apr. 2026
Birds and mammals distribute the berries widely, adding to its invasiveness.
—Sj McShane, Martha Stewart, 5 Apr. 2026
Buildings destroyed by shelling damage bats’ shelters, and explosions terrify the tiny mammals, experts say.
—ABC News, 5 Apr. 2026
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Dejanay Booth-Singleton, CBS News, 7 Apr. 2026
When science said dinosaurs were pea-brained and cold-blooded, humans took their demise as proof of the superiority of warm, clever mammals.
—Scottie Andrew, CNN Money, 5 Apr. 2026
Birds and mammals distribute the berries widely, adding to its invasiveness.
—Sj McShane, Martha Stewart, 5 Apr. 2026
Buildings destroyed by shelling damage bats’ shelters, and explosions terrify the tiny mammals, experts say.
—ABC News, 5 Apr. 2026
See All Example Sentences for mammal
Cite this Entry
“Mammal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mammal. Accessed 8 Apr. 2026.
Copy CitationKids Definition
mammal
noun
mam·mal
ˈmam-əl 
: any of a class of warm-blooded vertebrates that include human beings and all other animals that nourish their young with milk produced by mammary glands and have the skin usually more or less covered with hair
Medical Definition
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