catechin

from WordNet (r) 3.0 (2006)

catechin
    n 1: a tannic acid that is extracted from black catechu as a
         white crystalline substance

from The Collaborative International Dictionary of English v.0.48

Catechin \Cat"e*chin\, n. (Chem.)
   One of the tannic acids ({C15H14O6}), extracted from
   {catechu} as a white, crystalline substance; -- called also
   {catechuic acid}, {catechinic acid}, {cyanidol}, and
   {catechuin}. It is a flavonoid found generally in higher
   woody plants, and is used in dyeing and tanning.
   [1913 Webster +PJC]