Any one of a group of organic compounds derived by replacing one or more of the hydrogen atoms in ammonia by organic groups. Primary amines have one hydrogen replaced, e.g. methylamine, CH3NH2. They contain the functional group –NH2 (the amino group). Secondary amines have two hydrogens replaced, e.g. methylethylamine, CH3(C2H5)NH. Tertiary amines have all three hydrogens replaced, e.g. trimethylamine. Amines are produced by the decomposition of organic matter.