The fore part of the body, between the neck and the belly; the chest; as, the breast of a man or of a horse.
Either one of the protuberant glands, situated on the front of the chest or thorax in the female of man and of some other mammalia, in which milk is secreted for the nourishment of the young; a mamma; a teat.
The breast of a bird, or its upper chest, is where the powerful pectoral flying muscles can be found. These muscles take up a good portion of the birds' mass and are mainly employed to keep the wings beating steadily against the flow of air and the pull of gravity. In a number of birds it is speckled or spotted, as in most thrushes and the Northern Flicker; in other species it is often of a bright hue which contrasts sharply from the rest of the body (e.g. robins and bluebirds). It is very useful for the identification of many common types of birds, and should be distinguished from the belly area, which is lower on the underside and contains the legs.