• (a.) Pertaining to, or obtained from, the poppy or opium; specif. (Chem.), designating an acid related to aconitic acid, found in opium and extracted as a white crystalline substance.
Me·con'ic adjective [ Greek ... belonging to the poppy, from ... the poppy: confer French méconique .] Pertaining to, or obtained from, the poppy or opium; specif. (Chemistry) , designating an acid related to aconitic acid, found in opium and extracted as a white crystalline substance. 
meconic A reference to an acid found in opium.