Emily Dickinson Lexicon

ME-CON'I-NA, or MEC'O-NIN, n. [Gr. μηκων, a poppy.]

A proximate principle, and, as is supposed, one of the active principles of opium. It is composed of carbon, hydrogen and oxygen, without any nitrogen. It is not an alkaloid, but may yet prove to be an acid, to the suspicion of which, its composition would lead.