The Collaborative International Dictionary of English v.0.48:

Ellagic \El*lag"ic\, a. [F., fr. galle gall (with the letters
   reversed).] (Chem.)
   Pertaining to, or derived from, gallnuts or gallic acid; as,
   ellagic acid.
   [1913 Webster]

   Ellagic acid (Chem.), a white crystalline substance,
      C14H8O9, found in bezoar stones, and obtained by the
      oxidation of gallic acid.
      [1913 Webster]