What is the meaning of Buckthorn?

Any of several, often thorny shrubs or small trees, especially

  1. the buckthorn family (Rhamnaceae),
    1. especially genus Rhamnus,
      1. especially common buckthorn or purging buckthorn (Rhamnus cathartica).
    2. also alder buckthorn (Frangula), especially Frangula alnus).
  2. sea buckthorn (Hippophae, in family Elaeagnaceae).

the buckthorn family (Rhamnaceae),

  1. especially genus Rhamnus,
    1. especially common buckthorn or purging buckthorn (Rhamnus cathartica).
  2. also alder buckthorn (Frangula), especially Frangula alnus).

especially genus Rhamnus,

  1. especially common buckthorn or purging buckthorn (Rhamnus cathartica).

especially common buckthorn or purging buckthorn (Rhamnus cathartica).

also alder buckthorn (Frangula), especially Frangula alnus).

sea buckthorn (Hippophae, in family Elaeagnaceae).

Source: wiktionary.org