Breast – The outer, front part of the thorax, or the front part of the body, from the neck to the abdomen, of a person or animal.
God used this word 18 times in Scripture: 15 times to Israel in the Masoretic Text Old Testament; and 3 times to Israel in the Koine Greek Old Testament.
Today, when people talk about breasts, they are either referring to the mammary glands of a woman or the white-meat of a foul.
Although, still in common usage today, are words like breastplate, stand abreast, breast pockets, etc., and there is never any doubt about the meanings.