·noun Repeated composition; a combination of compounds.
II. Decomposition ·noun The state of being reduced into original elements.
III. Decomposition ·noun The act or process of resolving the constituent parts of a compound body or substance into its elementary parts; separation into constituent part; analysis; the decay or dissolution consequent on the removal or alteration of some of the ingredients of a compound; disintegration; as, the decomposition of wood, rocks, ·etc.