bosom vs breast

bosom and breast both are nouns.

Word	Noun	Adjective	Verb	Adverb
bosom	Yes	No	Yes	No
breast	Yes	No	Yes	No

As nouns, bosom and breast are synonyms defined as:

bosom and breast: either of two soft fleshy milk-secreting glandular organs on the chest of a woman

Other synonyms of bosom include boob, knocker, tit, titty.

As nouns, breast is a hypernym of bosom; that is, breast is a word with a broader meaning than bosom:

Other hypernyms of bosom include chest.

bosom (noun)	breast (noun)
a close affectionate and protective acceptance	the part of an animal's body that corresponds to a person's chest
cloth that covers the chest or breasts	either of two soft fleshy milk-secreting glandular organs on the chest of a woman
either of two soft fleshy milk-secreting glandular organs on the chest of a woman	the front of the trunk from the neck to the abdomen
a person's breast or chest	meat carved from the breast of a fowl
the locus of feelings and intuitions
the chest considered as the place where secret thoughts are kept

bosom (verb)	breast (verb)
hold (someone) tightly in your arms, usually with fondness	confront bodily
hide in one's bosom	reach the summit (of a mountain)
	meet at breast level