Dictionary.com
Thesaurus.com
Synonyms

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.

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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.

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:

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

A zoo is celebrating the birth of a giant anteater pup, which zoologists say is "considered the most threatened mammal in Central America".

From BBC

The system behind this process is buried deep in the hypothalamus, an ancient part of the brain shared by all mammals.

From Science Daily

“Yes, well, they also deliberately poison their own gardens, so we’re not talking about the brightest mammals in the macrocosm, are we?”

From Literature

He adds they are important parts of the food chain and support birds, small mammals, fish and other wildlife.

From BBC

The marine mammal, which is stuck on a sandbank, was first spotted in Lübeck Bay on Monday.

From BBC

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.