Definition of "elixir"

For Chinese alchemists, gold held the key to the Elixir, the Eastern equivalent of the Philosopher's Stone.

2002, Philip Ball, The Elements: A Very Short Introduction, Oxford, published 2004, page 59

The silver-bullet cancer cures of yesterday’s newsmagazine covers, like interferon and angiogenesis inhibitors, disappointed the breathless expectations, as have elixirs such as antioxidants, Vioxx, and hormone replacement therapy.

2015, The Boston Globe, Steven Pinker, The moral imperative for bioethics‎

The subcommittee's report to the Council on Pharmacy and Chemistry shows that the action of somnos is practically identical with that of a 5 per cent elixir of hydrated chloral.

1906, JAMA: The Journal of the American Medical Association, volume 47, pages 872–875