We found 26 dictionaries that define the word St John's wort:

General (11 matching dictionaries)

1. St. John's wort: Merriam-Webster
2. St. John's wort, St. Johns wort: Oxford Learner's Dictionaries
3. St John's wort: Vocabulary.com
4. St. John's wort: Wordnik
5. St John's wort: Wiktionary
6. St. John's-wort, st-john's-wort, st-johns-wort, st.-john's-wort, st.-johns-wort, st. john's wort, st. johns wort, st john's wort, st johns wort: Dictionary.com
7. St. John's Wort, St John's Wort, St Johns Wort, St. John's wort, St John's wort, St Johns wort: Wikipedia, the Free Encyclopedia
8. St john's wort: Rhymezone
9. st johns wort: FreeDictionary.org
10. st john's wort: Mnemonic Dictionary
11. St John's wort: TheFreeDictionary.com

Art (1 matching dictionary)

12. Natural Magick (No longer online)

Computing (1 matching dictionary)

13. St.-John's-wort, St. John's wort, St John's wort: Encyclopedia

Medicine (10 matching dictionaries)

14. Dorland's Illustrated Medical Dictionary (No longer online)
15. St John's wort: MedTerms.com Medical Dictionary
16. Breast Cancer Talking Dictionary (No longer online)
17. St. John's wort: Merck Manuals
18. AIDS Medical Glossary and Drug Chart (No longer online)
19. St. John's Wort: Glossary of Herbs, Botanicals and Other Products
20. St. John's wort: Dictionary of Cancer Terms
21. St. Johns Wort, St Johns Wort, St. John's wort, St John's wort: Medical dictionary
22. St John's wort: Drug Medical Dictionary
23. Hyperdictionary (No longer online)

Science (2 matching dictionaries)

24. St. John's Wort: Botanical Name listing of Plants
25. A Modern Herbal, 1931, by Mrs. M. Grieve (No longer online)

Sports (1 matching dictionary)

26. St. John's Wort: Body Building

Definitions from Wiktionary (St John's wort) ▸ noun:  Alternative form of St. John's wort [Any of several plants, of the genus Hypericum, especially Hypericum perforatum, that have yellow flowers and traditionally ward off evil.] Phrases: common st johns wort, marsh st johns wort, shrubby st johns wort, creeping st johns wort, great st johns wort, more... ▸ Words similar to St John's wort ▸ Usage examples for St John's wort ▸ Idioms related to St John's wort ▸ Wikipedia articles (New!) ▸ Words that often appear near St John's wort ▸ Rhymes of St John's wort ▸ Invented words related to St John's wort