elixir of life
；medicine of immortality
例句：
在《海经》中，昆仑之门被逐渐打开，成为方士采集不死药的园圃。
In the Classic of Sea, Mt. Kunlun is a deemed as a garden for immortal herbs, where alchemists could come and collect immortal herbs.
嫦娥将药藏进梳妆台的百宝匣里，不料被小人蓬蒙看见了，他想偷吃不死药自己成仙。
The moon will be the treasure box drugs into the dresser, but was seen by Peng Meng, he wanted to steal their immortal immortality drug.
希望能帮助到你，望采纳！