The Collaborative International Dictionary of English v.0.48:

Myrobalan \My*rob"a*lan\, Myrobolan \My*rob"o*lan\, n. [L.
   myrobalanum the fruit of a palm tree from which a balsam was
   made, Gr. myroba`lanos; my`ron any sweet juice distilling
   from plants, any prepared unguent or sweet oil + ba`lanos an
   acorn or any similar fruit: cf. F. myrobolan.]
   A dried astringent fruit much resembling a prune. It contains
   tannin, and was formerly used in medicine, but is now chiefly
   used in tanning and dyeing. Myrobolans are produced by
   various species of Terminalia of the East Indies, and of
   Spondias of South America.
   [1913 Webster]