What is "meconin"

Meconin \Mec"o*nin\, n. [Cf. F. m['e]conine.] (Chem.) A substance regarded as an anhydride of meconinic acid, existing in opium and extracted as a white crystalline substance. Also erroneously called meconina, meconia, etc., as though it were an alkaloid.

n. (context chemistry English) A substance regarded as an anhydride of meconinic acid, found in opium.