A bitter colourless powder, an alkaloid derived from cinchona bark, used to treat malaria and as an ingredient of tonic water. (noun)
Examples of word quinine
Many men indulge in what we call the quinine habit.
For example, the FDA ordered a number of manufacturers to stop marketing unapproved drugs that contain quinine, which is often used to treat leg cramps.
I hesitate to advise this, because I fear to induce any one to abandon quinine, which is the great weapon against malaria, and not from any want of faith in Dr. Plehn, for he has studied malarial fevers in Cameroon with the greatest energy and devotion, bringing to bear on the subject a sound German mind trained in a German way, and than this, for such subjects, no better thing exists.
In the 1790s, Hahnemann undertook an experiment with Peruvian bark, the source of quinine, which is now used to treat malaria.
But she had no idea whether it was even called quinine here, or how it was administered.