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

Paleontologists now agree that many, if not all, dinosaurs maintained constant high body temperatures, just like birds and mammals do today. —Hans Sues, Discover Magazine, 15 Aug. 2024

Small rodents, monkeys, and mammals can pass the virus on to humans but outbreaks typically take off when humans infect each other. —Jess Craig, Vox, 15 Aug. 2024

Row covers, fruit protection bags, and companion planting all deter birds, mammals, and insect pests that damage garden plants and attract snakes. —Lauren Landers, Better Homes & Gardens, 13 Aug. 2024

The virus detected in nearby dairy herds spilled over to mammals and wild birds on and near these premises, the state veterinarian said. —Eduardo Cuevas, USA TODAY, 17 Aug. 2024

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

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