opiammoneChem.|ˈəʊpɪəməʊn| [f. opian- + ammonia.] An amide of opianic acid C20H19NO8, obtained by evaporating a solution of opianic acid in ammonia. 1845Penny Cycl.Suppl. I. 348 Opiammon.1866–77Watts Dict.Chem. IV. 207 Opiammone is a pale yellow crystalline powder.