Definition of "cascara"

cascara

noun
plural cascaras
1. A North American buckthorn (Frangula purshiana, syn. Rhamnus purshiana) whose bark is used as a laxative.
2. A laxative drug or preparation based on this plant.
  Quotations
  "That's as bitter as a dose of cascara."
  1972, John O'Grady, It's Your Shout, Mate, Ure Smith, page 60
3. Dried coffee cherry fruit used in teas and other drinks.