Con`tra*yer"va (?), n. [Sp. contrayerba, literally, a counter herb, hence, an antidote for poison, fr. l. contra + herba herb.] Bot.
A species of Dorstenia (D. Contrayerva), a South American plant, the aromatic root of which is sometimes used in medicine as a gentle stimulant and tonic.
© Webster 1913.