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secret medicine; secret remedy; nostrum
wonder drug; excellent remedy
古い文献に秘薬の調合法が記されていた。
The method of preparing the secret medicine was recorded in old documents.
その秘薬は山奥の薬草から作られるという。
It is said that the secret medicine is made from herbs deep in the mountains.
王に献上する秘薬を調合する任務を受けた。
I received the task of preparing a secret medicine to present to the king.