Webster's Revised Unabridged Dictionary · 1913

Rhamnus

Rhamnus , noun

[New Latin, from Greek "ra`mnos a kind of prickly shrub; compare Latin rhamnos.]

(Botany) A genus of shrubs and small trees; buckthorn. The California Rhamnus Purshianus and the European Rhamnus catharticus are used in medicine. The latter is used for hedges.