1.A shrubby tree of the U. S. Pacific coast (Rhamnus purshianus or Rhamnus purshiana), whose bark is the cascara sagrada, used as a mild cathartic or laxative.
2.A deciduous tree of SE U.S. and Mexico.
3.A shrubby tree of southern U.S. (Cotinus obovatus) having large plumes of feathery flowers resembling puffs of smoke; called also American smoke tree.