胸|むねmune[2]odaka (tail-high)

1. nounchest; breastむな is usually used in compounds
2. nounbreasts; bosom; bust
3. nounheart
4. nounlungs
5. nounstomach
6. nounheart; mind; feelings
   その亡命者ぼうめいしゃは故国ここくへの思おもいに胸むねを焦こがした。↗

   The exile yearned for his home.

• Synonym胸部きょうぶWrittenWritten, medical and formal term for the chest, as in 「胸部レントゲン」. Unlike 「胸」, it never refers to the heart or feelings.
• Synonym胸元むなもとNeutralThe upper chest, often near a garment's opening, as in 「胸元が開いた服」. Mostly about clothing; 「胸」 is the whole chest.
• Synonym乳房ちぶさNeutralStrictly the breasts, in physiological or medical contexts, as in 「乳房のしこり」. 「胸」 is a softer, more indirect way to refer to them.
• SynonymおっぱいCasualBaby talk or slang for breasts or breast milk, casual and sometimes cheeky; not used in formal settings.
• SynonymバストNeutralLoanword mostly for a woman's bust measurement, as in 「バストサイズ」; also a bust sculpture. Used for clothing and body shape.
• Synonym胸襟きょうきんWrittenWritten term, originally the chest and collar; mostly seen in 「胸襟を開く」, to open one's heart.
• Synonym胸間きょうかんWrittenRare written word for the chest area or the heart within. In everyday speech say 「胸」 or 「胸の内」 instead.
• Synonym胸板むないたNeutralThe front of the chest, often when describing build, as in 「厚い胸板」. Body part only; 「胸」 can also mean the heart or feelings.
• Synonym胸先むなさきNeutralThe chest or bosom area. Uncommon in daily use; say 「胸元」 or 「胸」 instead.
• Related腹はらNeutralThe belly or abdomen, next to the chest. Also one's true intentions, as in 「腹を割る」; in the mind sense it is close to 「胸」 but leans toward one's thoughts.
• Related心根こころねWrittenOne's innermost nature or character, as in 「心根の優しい人」; it stresses what a person is at heart, while 「胸」 leans toward feelings.
• Related胸三寸むねさんずんWrittenIdiomatic written expression for the plans and judgment one holds in mind, as in 「胸三寸に納める」; it stresses inner deliberation.
• Related胸糞むなくそCasualVulgar slang, mostly in 「胸糞が悪い」, for feeling thoroughly sick or upset; strongly coarse compared with 「胸」.
• Related胸懐きょうかいWrittenRare written word for the feelings and thoughts held in one's chest. In daily speech say 「胸の内」 or 「思い」.
• Related胸臆きょうおくWrittenRare written word for one's innermost thoughts. In everyday speech say 「胸の内」 or 「本音」.

「胸」 covers both the body and the heart. Medical or formal contexts use 「胸部」; 「胸元」 is the area near a neckline; 「バスト」 is a bust measurement. Breasts are 「乳房」 in medical talk, 「おっぱい」 casually. For the heart, everyday speech keeps 「胸」 or 「胸の内」; written prose may use 「胸襟」 or 「胸懐」. 「腹」 is the belly or one's true intentions.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. （むね）人体じんたいの一部いちぶで胴体どうたい前方ぜんぽうの首くびと腹部ふくぶの間あいだにあって、肋骨ろっこつにより形作かたちづくられている部分ぶぶん。