breast : 指人或动物的胸部或胸部的前面，也指男人或女人的乳房。
- When a woman becomes pregnant her breasts tend to grow larger.
- breast cancer
- Do you think she's had breast implants?
- A robin is easy to identify because of its red breast.
- The dagger entered his breast.
bosom : 文学用词，与breast同义，特指女性的乳房，也可用作比喻。
- a large/ample bosom
- She held him tightly to her bosom.
- A dark jealousy stirred in his bosom.
chest : 指胸膛，即肋骨所包围的部分。
- He was shot in the chest at point blank range.
- He folded his arms across his chest.
- His shirt was open to the waist revealing a very hairy chest.
- She went to the doctor complaining of chest pains.