Definition of mammal in English:



  • A warm-blooded vertebrate animal of a class that is distinguished by the possession of hair or fur, females that secrete milk for the nourishment of the young, and (typically) the birth of live young.

    • ‘They inhabited a world that was dominated by a different kind of animal - the mammal.’
    • ‘It provides the growing young with everything it wants, and only mammals produce milk.’
    • ‘Dolphins are mammals and as such are warm-blooded and bear live young, which they suckle.’
    • ‘The decaying wood also becomes home to a range of insects and small mammals.’
    • ‘Recently, the rat became the third mammal for which the complete genome was sequenced.’
    • ‘The male feeds the female while she incubates, catching small mammals and birds and bringing them back to the nest.’
    • ‘This bulky animal is one of the most dangerous mammals to be found anywhere.’
    • ‘The domestic animal is the first mammal known to die of the disease in Europe.’
    • ‘The island refuges of some species are also under threat from imported mammals such as rats and hedgehogs.’
    • ‘The lack of suitable nest sites has also resulted in increased predation by corvids and mammals on the eggs and chicks.’
    • ‘Animal pathologists found the mammals had suffered internal bleeding in the ears and the brain.’
    • ‘The teeth and their pattern of wear are unlike that seen in any modern mammal so what this animal ate is something of a mystery.’
    • ‘Certainly, a lot of changes would have to occur for a land mammal to live in the sea.’
    • ‘West Nile Virus is found mainly in birds, though it is also found in horses and other mammals.’
    • ‘Their prey consists mainly of birds and small mammals such as rats and agoutis.’
    • ‘Nothing is more remarkable than the effects of habit in herbivorous mammals.’
    • ‘The sloths and armadillos are rather odd mammals characteristic of South America.’
    • ‘Unlike mammals, chicks do not feed on milk formula as their stomachs cannot digest it.’
    • ‘The domes will contain different freshwater environments containing fish and aquatic mammals.’
    • ‘Some mammals can distinguish between and respond to the alarm calls of other mammal and bird species.’


Early 19th century: anglicized form (first used in the plural) of modern Latin mammalia, neuter plural of Latin mammalis (adjective), from mamma ‘breast’ (see mamma).