buckthorn: Meaning and Definition of

buck•thorn

1. any of several, sometimes thorny trees or shrubs belonging to the genus Rhamnus, esp. R. frangula, the bark of which is used in medicine. Cf. buckthorn family.
2. a tree or shrub belonging to the genus Bumelia, of the sapodilla family, esp. B. lycioides, a thorny tree having elliptic leaves and large clusters of white flowers, common in the southern and part of the central U.S.