mammal

American  

[mam-uhl] / ˈmæm əl /

noun

1. any vertebrate of the class Mammalia, having the body more or less covered with hair, nourishing the young with milk from the mammary glands, and, with the exception of the egg-laying monotremes, giving birth to live young.

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mammal British  

/ ˈmæməl, mæˈmeɪlɪən /

noun

1. any animal of the Mammalia, a large class of warm-blooded vertebrates having mammary glands in the female, a thoracic diaphragm, and a four-chambered heart. The class includes the whales, carnivores, rodents, bats, primates, etc

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mammal Scientific  

/ măm′əl /

1. Any of various warm-blooded vertebrate animals of the class Mammalia, whose young feed on milk that is produced by the mother's mammary glands. Unlike other vertebrates, mammals have a diaphragm that separates the heart and lungs from the other internal organs, red blood cells that lack a nucleus, and usually hair or fur. All mammals but the monotremes bear live young. Mammals include rodents, cats, dogs, ungulates, cetaceans, and apes.

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Other Word Forms

• mammal-like adjective
• mammalian adjective
• mammallike adjective

Etymology

Origin of mammal

First recorded in 1820–30; as singular of New Latin Mammalia, neuter plural of Late Latin mammālis “of the breast”; equivalent to mamma ² + -al ¹

Compare meaning

How does mammal compare to similar and commonly confused words? Explore the most common comparisons:

• marsupial vs. mammal

Example Sentences

New research published Thursday in the journal Science details how the whiskers that cover an elephant's trunk have unique properties that lend the largest land mammals remarkable dexterity.

From Barron's

It has led to the deaths of more than 400 million poultry worldwide and has infected dairy cows, mink, foxes, bears, otters, and many other mammals and wild birds.

From Science Daily

It may have resembled a lizard, but it lived before reptiles and mammals branched into separate evolutionary paths, so it was not technically a reptile.

From Science Daily

The stunning Sierra Nevada red fox is one of the nation’s rarest and most critically threatened mammals with fewer than 50 believed to remain in the Sierra.

From Los Angeles Times

It’s not exactly a chicken and dinosaur-egg question, but which came first, the mammal or the giant lizard?

From The Wall Street Journal

Related Words

• beast
• creature
• vertebrate