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to confide; to reveal; to disclose; to lay bare; to speak frankly; to open (one's heart)
誰にも言えなかった深い悩みを親友に打ち明けた。
I confided my worries to my best friend.
彼は長年隠していた重大な秘密を打ち明けてくれた。
He revealed his secret to me.
本当の気持ちを打ち明ける勇気がない。
I don't have the courage to reveal my true feelings.