• St John's wort, Saint John's wort

• (General American) IPA^(key): /seɪnt ˈd͡ʒɑnz wɝt/, enPR: sānt jŏnz wûrt
• (Received Pronunciation) IPA^(key): /sən(t) ˈd͡ʒɒnz wɜːt/

St. John's wort (usually uncountable, plural St. John's worts)

1. Any of several plants, of the genus Hypericum, especially Hypericum perforatum, that have yellow flowers and traditionally ward off evil.

   Synonym: John's wort

   • [1612, Michael Drayton, Poly-Olbion song 13 p. 218[1]:

     that hearbe we call S. John]

   • 1828, Thomas Keightley, The Fairy Mythology, volume I, London: William Harrison Ainsworth, page 140:

     It is also necessary to watch cattle so that they may not graze in any place where the Elle-people have been. If any animal goes to a place where the Elle-people have spit or done what is worse, it is attacked by some grievous disease, which can only be cured by giving it a handful of St. John's wort, which was pulled at twelve o'clock on St. John's night.

   • 1940, Rosetta E. Clarkson, Green Enchantments: The Magic Spell of Gardens, The Macmillan Company, page 258:

     Peony would keep away any kind of storms. Mugwort hung over doorways on Midsummer's Day, June 24, would keep off lightning, as St. John's-Wort would if gathered before sunrise on that day.

   • 2013 March, David S. Senchina, “Athletics and Herbal Supplements”, in American Scientist‎^[2], volume 101, number 2, archived from the original on 16 May 2013, page 134:

     Athletes' use of herbal supplements has skyrocketed in the past two decades. At the top of the list of popular herbs are echinacea and ginseng, whereas garlic, St. John's wort, soybean, ephedra and others are also surging in popularity or have been historically prevalent.

2. (uncountable) The plant prepared as a medication.

• Hypericum on Wikipedia.Wikipedia
• Hypericum perforatum on Wikipedia.Wikipedia
• Hypericum on Wikispecies.Wikispecies