məˈmālēə, -lyə noun plural
Usage: capitalized
Etymology: New Latin, from Late Latin, neuter plural of mammalis of the breast, from Latin mamma breast + -alis -al
: the highest class of Vertebrata comprising man and all other animals that nourish their young with milk, that have the skin usually more or less covered with hair, that have mammary glands, a mandible articulating directly with the squamosal, a chain of small ear bones, a brain with four optic lobes, a muscular diaphragm separating the heart and lungs from the abdominal cavity, only a left aortic arch, warm blood containing red cells without nuclei except in the fetus, and embryos developing both amnion and allantois, and that except in the monotremes reproduce viviparously — compare allotheria , eutheria , metatheria , prototheria , theria