Saint John's-wort

(Bot.) any plant of the genus Hypericum, most species of which have yellow flowers; - called also John's-wort.

See also: Saint

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
Conducted by the Good Housekeeping Institute, the consumer research laboratory of Good Housekeeping magazine, the study measured what are thought to be Saint John's-wort's active ingredients, hypericin and pseudohypericin.