资料来源 : Webster's Revised Unabridged Dictionary (1913)

Castor bean \Cas"tor bean`\ (Bot.)
   The bean or seed of the castor-oil plant ({Ricinus communis},
   or {Palma Christi}.)

资料来源 : WordNet®

castor bean
     n : the toxic seed of the castor-oil plant; source of castor oil