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

Today, the wetland is home to an array of species, including approximately 39 mammals, 200 birds, 38 fish, and several reptiles and amphibians, including Siberian salamanders. —Kristen Pope, Travel + Leisure, 8 June 2024

Exhibits cover the ages pre- and post-dinosaurs, so patrons can learn about ancient plants, reptiles and mammals, and how the climate has evolved. —Tiney Ricciardi, The Denver Post, 2 June 2024

Control snails, slugs and roly-polies (aka pill bugs) with Sluggo Plus, an iron phosphate product that is not toxic to birds, mammals (including us), caterpillars, butterflies, etc. —Nan Sterman, San Diego Union-Tribune, 1 June 2024

Santa Cruz, California — New mug shots have emerged of otter 841, America's most wanted marine mammal. —Carter Evans, CBS News, 1 June 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