mammal

noun

mam·​mal ˈma-məl 

: 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

mammalian

mə-ˈmā-lē-ən 

ma-

adjective or noun

mammal-like

ˈma-məl-ˌlīk 

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

Increasingly, a different kind of safari is emerging; one where flowers are as fascinating as mammals, where conservation stories take center stage, and where wellness, history and community become just as important as wildlife sightings. — Sarah Kingdom, Forbes.com, 17 July 2026

Echidnas, similar to the platypus, are monotremes, egg-laying mammals that typically produce only one egg per breeding season. — Saman Shafiq, USA Today, 16 July 2026

These members of the order of Carnivora, which includes bears, wolves, felines, seals, and many other mammals that specialize in eating flesh, have found a way to reorganize themselves to take full advantage of all that city life has to offer. — Literary Hub, 15 July 2026

Even mammals such as squirrels, which normally eat nuts that are safe for human consumption, will occasionally munch on mushrooms and nuts that are toxic to humans. — Tim MacWelch, Outdoor Life, 15 July 2026

Word History

Etymology

from base of New Latin Mammalia (Linnaeus), class name, noun derivative from neuter plural of mammālis, from Latin mamma "breast, udder" + -ālis -al entry 1 — more at mamma entry 1

First Known Use

1811, in the meaning defined above

Rhymes for mammal

• camel
• hamel
• hamil
• trammel
• enamel
• glutamyl

Kids 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

mammal

noun

mam·​mal ˈmam-əl 

: any of the higher vertebrate animals comprising the class Mammalia

mammalian

mə-ˈmā-lē-ən, ma- 

adjective or noun