Saint-John's-wort

noun

ˈsānt-ˈjänz-ˌwərt  -ˌwȯrt 

variants or Saint John's wort or St. John's wort

1

: any of a large genus (Hypericum of the family Hypericaceae, the Saint-John's-wort family) of cosmopolitan herbs and shrubs with showy pentamerous yellow flowers

2

: the dried aerial parts of a Saint-John's-wort (Hypericum perforatum) that are held to relieve depression and are used in herbal remedies and dietary supplements

Illustration of Saint-John's-wort

• Saint-John's-wort 1

Examples of Saint-John's-wort in a Sentence

Recent Examples on the Web

Saint-John's-Wort Saint-John's-wort is an herbal supplement known for its antidepressant effects. — Sohaib Imtiaz, Verywell Health, 17 Apr. 2025

Word History

Etymology

St. John the Baptist

First Known Use

15th century, in the meaning defined at sense 1

Medical Definition

Saint-John's-wort

noun

variants or Saint John's wort or St. John's wort

-ˈjänz-ˌwərt  -ˌwȯ(ə)rt 

1

: any of a genus (Hypericum of the family Hypericaceae, the Saint-John's-wort family) of herbs and shrubs with showy yellow flowers

especially : one (H. perforatum) of dry soil, roadsides, pastures, and ranges that contains a photodynamic pigment causing dermatitis due to photosensitization in sheep, cattle, horses, and goats when ingested see hypericism

2

: the dried aerial parts of a Saint-John's-wort (Hypericum perforatum) that are held to relieve depression and are used in herbal remedies and dietary supplements