The Collaborative International Dictionary
orsellic acid
Lecanoric \Lec`a*no"ric\, a. (Chem.) Pertaining to, or designating, an organic acid which is obtained from several varieties of lichen ( Lecanora, Roccella, etc.), as a white, crystalline substance, and is called also orsellic acid, diorsellinic acid, lecanorin, etc.
Wiktionary
orsellic acid
n. (context organic compound English) An acid found in certain lichens; lecanoric acid.