n. [ Sinapis + melamine. ] (Chem.) A bitter white crystalline nitrogenous substance, obtained indirectly from oil of mustard and ammonia; -- called also allyl melamine. [ 1913 Webster ]

n. [ Pref. di- + amine. ] (Chem.) A compound containing two amido groups united with one or more basic or positive radicals, -- as contrasted with a diamide. [ 1913 Webster ]

☞ In chemical nomenclature, if any amine or diamine is named by prefixing the nitrogen group, the name of the latter takes the form of amido, diamido, etc., thus ethylene diamine, C2H4.(NH2)2, is also called diamido-ethylene. [ 1913 Webster ]