Cascara buckthorn \Cas"ca*ra buck"thorn`\ (Bot.) The buckthorn ({Rhamnus Purshiana}) of the Pacific coast of the United States, which yields cascara sagrada.
cascara buckthorn n : shrubby tree of the Pacific coast of the United States; yields cascara sagrada [syn: {bearberry}, {bearwood}, {chittamwood}, {chittimwood}, {Rhamnus purshianus}]