The Collaborative International Dictionary of English v.0.48:
Quercitin \Quer"ci*tin\ (kw[~e]r"s[i^]*t[i^]n), n. (Chem.) A yellow crystalline substance, occurring quite widely distributed in the vegetable kingdom, as in apple-tree bark, horse-chestnut leaves, etc., but originally obtained by the decomposition of quercitrin. Called also meletin. [1913 Webster]