胸むねに納おさめる

expression, ichidan verb

keep to oneself; keep secret; keep inside

Used when someone keeps a thought, feeling, or secret inside without revealing it to others. Often implies a deliberate decision to not share.

• 彼かれはその秘ひ密みつを胸むねに納おさめて、誰だれにも話はなさなかった。

  He kept the secret to himself and told no one.

• 感かん謝しゃの気き持もちを胸むねに納おさめて、静しずかに会かい場じょうを後あとにした。

  I kept my gratitude inside and quietly left the venue.