Translation guide
The English word 'breasts' can refer to the anatomical body part, the chest area, or be used in figurative expressions. In Japanese, the most common and neutral term is 胸 (mune), which covers both the chest and breasts. More specific or clinical terms exist, but are less common in everyday speech.
Referring to the breasts as a body part in a neutral, everyday context.
The most common and neutral word for both 'chest' and 'breasts'. Used in everyday conversation.
彼女は胸に手を当てた。
She put her hand on her chest/breast.
Colloquial and somewhat childish term for breasts, often used by children or in casual, intimate settings. Can also refer to breast milk.
赤ちゃんがおっぱいを飲んでいる。
The baby is drinking breast milk.
Clinical or anatomical term for 'breast'. Used in medical contexts or formal writing.
乳房のしこりに気づいた。
I noticed a lump in my breast.
Loanword from English 'bust', used mainly in fashion, beauty, or when discussing breast size.
バストサイズを測る。
Measure bust size.
Referring to the chest region, not specifically female breasts.
Again, 胸 is the standard word for the chest area. Context clarifies whether it means chest or breasts.
胸が痛い。
My chest hurts.
Formal or medical term for the chest region.
胸部レントゲンを撮る。
Take a chest X-ray.
Using 'breast' or 'chest' metaphorically to refer to emotions or inner feelings.
In Japanese, 胸 is often used metaphorically for the heart or seat of emotions, similar to English 'heart' or 'bosom'.
胸が高鳴る。
My heart pounds (with excitement).
胸がいっぱいになる。
To be overwhelmed with emotion.
Literally 'heart', used for emotions. Not a direct translation of 'breasts', but often used in similar figurative contexts.
English speakers often use 'breasts' where Japanese would simply use 胸 (mune). Using 乳房 (nyūbō) in casual conversation can sound overly clinical or awkward. Stick to 胸 unless you need to be anatomically precise.
胸 is neutral and can be used by anyone. おっぱい is informal and often has a childish or intimate connotation. Avoid using おっぱい in formal situations or with people you are not close to.
My heart aches.