Contrayerva \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} ({Dorstenia Contrayerva}), a South
American plant, the aromatic root of which is sometimes used
in medicine as a gentle stimulant and tonic.
[1913 Webster]