胸襟|きょうきんkyoukin[0]heiban (flat)

1. nounone's heart

• Synonym内心ないしんWrittenWritten. Points to one's real thoughts, often concealed intentions; unlike the headword, it does not fit the 「開く」 idiom.
• Synonym心根こころねWrittenWritten. Points to the true nature deep in one's heart, leaning toward character and disposition.
• Synonym心こころNeutralNeutral and the everyday default. Covers mind, feelings and spirit, with the broadest range of these words.
• Synonym胸懐きょうかいWrittenWritten and rare. Points to what one holds in the heart; in sense it comes closest to 「胸襟」 itself.
• Synonym胸臆きょうおくWrittenWritten and rare. Points to feelings kept hidden deep in one's heart.

「胸襟」 appears mostly in 「胸襟を開く」, opening one's heart to deal frankly with others, and also in 「胸襟を吐露する」. For inner thoughts say 「内心」 or 「胸中」; for one's true nature say 「心根」; 「心」 is the everyday all-purpose word.

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

1. 胸むねと襟えり。
2. 胸むねの内うち。心中しんじゅう。