The Collaborative International Dictionary
Lactucone
Lactucone \Lac*tu"cone\, n. [From Lactuca.] (Chem.) A white, crystalline, tasteless substance, found in the milky sap of species of Lactuca, and constituting an essential ingredient of lactucarium.
Wiktionary
lactucone
n. (context organic compound English) A white, crystalline, tasteless substance found in the milky sap of species of Lactuca, and constituting an essential ingredient of lactucarium.