any of several thorny small-flowered shrubs of the genus Rhamnus, esp the Eurasian species R. cathartica, whose berries were formerly used as a purgative: family Rhamnaceae
See also sea buckthorn
Word origin
C16: from buck1 (from the spiny branches, imagined as resembling antlers) + thorn
buckthorn in American English
(ˈbʌkˌθɔrn)
noun
1.
any of a genus (Rhamnus) of thorny trees or shrubs of the buckthorn family, bearing small greenish flowers and purple berries
2.
any of a genus (Bumelia) of trees of the sapodilla family, native to the S U.S.
adjective
3.
designating a family (Rhamnaceae, order Rhamnales) of dicotyledonous shrubs and trees, includingthe cascara, jujube, and redroot