1) Autoxidationreduction 
disproportion; disproportionate; disproportionating. A reaction involving a substance that produces two different forms of the substance, one more oxidized and the other more reduced than the original.
Disproportionation is a specific type of redox reaction in which a species is simultaneously reduced and oxidized to form two different products. For example: the UV photolysis of mercury(I) chloride Hg2Cl2 → Hg + HgCl2 is a disproportionation. Mercury (I) is a diatomic dication {chem|Hg|2|2+}. In this reaction the chemical bond in the molecular...
(from the article `halogen element`) ...the nonmetal is both oxidized and reduced (i.e., its oxidation number is increased and decreased, respectively). A reaction in which the same ... [2 related articles]
<chemistry> The splitting of a chemical compound into two new compounds, one more oxidized and one more reduced than the original compound. ... (11 Jan 1998) ... 
A chemical reaction in which a single reactant breaks up to produce two different products
the simultaneous oxidation and reduction of a substance reacting with itself, thereby forming two dissimilar molecules, as 2CH→CH+CH.