Source : Webster's Revised Unabridged Dictionary (1913)

Convallamarin \Con*val"la*ma`rin\, n. [Convallaria + L. amarus
   bitter.] (Chem.)
   A white, crystalline, poisonous substance, regarded as a
   glucoside, extracted from the lily of the valley
   ({Convallaria Majalis}). Its taste is first bitter, then
   sweet.