The Collaborative International Dictionary of English v.0.48:

Morin \Mo"rin\, n. (Chem.)
   A yellow crystalline substance (C15H10O7) of acid
   properties extracted from fustic (Chlorophora tinctoria
   syn. Maclura tinctoria, formerly called Morus tinctoria);
   -- called also moric acid and natural yellow 8. It is
   used as a dye for wool, giving a color from lemon yellow
   through olive to olive brown, depending on the metal with
   which it is mordanted.
   [1913 Webster +PJC]