The Collaborative International Dictionary
Quercitannic
Quercitannic \Quer`ci*tan"nic\ (kw[~e]r`s[i^]*t[a^]n"n[i^]k), a. [L. quercus an oak + E. tannic.] (Chem.) Pertaining to, or designating, a tannic acid found in oak bark and extracted as a yellowish brown amorphous substance.
Wiktionary
quercitannic
a. Of or pertaining to quercitannic acid or its derivatives